DEPARTMENT OF LICENSING AND REGULATORY AFFAIRS  
PUBLIC SERVICE COMMISSION  
PRESERVATION OF RECORDS OF ELECTRIC, GAS, AND STEAM UTILITIES  
(By authority conferred on the public service commission by section 5 of 1919 PA 419 and  
section 4 of 1939 PA 3, MCL 460.4)  
PART I. GENERAL PROVISIONS  
R 460.2501 Scope.  
Rule 1. (1) These rules apply to all books of account and other records prepared by or on  
behalf of the public utility. See R 460.2582 for records that come into the possession of the  
public utility in connection with the acquisition of property, such as a purchase, consolidation, or  
merger.  
(2) These rules shall not be construed as excusing compliance with any other lawful  
requirement for the preservation of records for periods longer than those prescribed in these  
rules. When a gas utility collects rates authorized by this commission based on increased supplier  
rates collected under bond under the authority of the Federal Energy Regulatory Commission  
(FERC), this utility shall maintain sufficient gas consumption records to enable the calculation of  
refunds to individual customers as may be ordered by the Michigan public service commission.  
This requirement continues in effect until final action by FERC or until the final decree of the  
court, if appealed to the court, and until the time when the Michigan public service commission  
has entered its order authorizing appropriate refunds if applicable.  
(3) Unless otherwise specified in part 2 of these rules, duplicate copies of records may be  
destroyed at any time if the duplicate copies do not contain significant information not shown on  
the originals.  
(4) Records other than those listed in part 2 of these rules may be destroyed at the option of  
the public utility if records that are used in place of those listed will be preserved for the periods  
prescribed for the records used for substantially similar purposes and if the retention of records  
pertaining to added services, functions, and plant, the establishment of which cannot be presently  
foreseen, will conform to the principles embodied in these rules.  
(5) Upon written request of a public utility, or on its own motion, the commission may  
waive any requirements of these rules when it determines that the waiver will further the  
effective and efficient administration of these rules and is in the public interest.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2502 Designation of supervisory official.  
Rule 2. A public utility subject to these rules shall designate 1 or more persons to be  
officially responsible for the supervision of the utility’s program for the preservation and  
authorized destruction of its records.  
Page 1  
History: 1979 AC; 1980 AACS.  
R 460.2503 Protection and storage of records.  
Rule 3. The public utility shall provide reasonable protection for records subject to these  
rules from damage by fires, floods, and other hazards and shall safeguard the records from  
unnecessary exposure to deterioration. The public utility shall also operate a back-up system to  
preserve electronic information and records that are required to be retained under these rules.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2504 Index of records.  
Rule 4. At each office of a public utility where records are kept or stored, such records as  
are herein required to be preserved shall be so arranged, filed, and currently indexed that they  
may be readily identified and made available to representatives of the commission.  
History: 1979 AC; 1980 AACS.  
R 460.2505 Preservation of record storage media generally.  
Rule 5. A public utility has the flexibility to select its own storage media, subject to the  
following conditions:  
(a) The storage media selected must have a life expectancy at least equal to the applicable  
record retention period provided in part 2 of these rules unless there is a quality transfer from 1  
media to another with no loss of data.  
(b) A public utility shall implement internal control procedures that ensure the reliability of,  
and ready access to, data stored on machine-readable media. Internal control procedures shall be  
documented by a responsible supervisory official.  
(c) A transfer of data from 1 media to another must be verified for accuracy and  
documented. Software and hardware required to produce readable records shall be retained for  
the same period as the media format is used.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2505a Rescinded.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2505b Rescinded.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
Page 2  
R 460.2505c Rescinded.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2506 Destruction of records.  
Rule 6. At the expiration of the retention period, a public utility may use any appropriate  
method to destroy records as long as the method ensures the full destruction of information  
contained in the documents that is forbidden by law from being divulged to unauthorized  
persons.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2507 Premature destruction or loss of records.  
Rule 7. When any records are destroyed before the expiration of the prescribed period of  
retention, a certified statement listing, as far as may be determined, the records destroyed and  
describing the circumstances of accidental or other premature destruction shall be filed with the  
commission within 90 days from the date of discovery of such destruction. Discovery of the loss  
of records is to be treated in the same manner as in the case of premature destruction.  
History: 1979 AC; 1980 AACS.  
R 460.2508. Rescinded.  
History: 1979 AC; 1980 AACS.  
R 460.2509 Retention periods designated “Destroy at option.”  
Rule 9. Use of the retention period, “Destroy at option,” in these rules authorizes the  
destruction of records at management’s discretion if the destruction of the records does not  
conflict with other legal retention requirements or usefulness of such records in satisfying  
pending regulatory actions or directives.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
PART 2. SCHEDULE OF RECORDS AND PERIODS OF RETENTION  
R 460.2511 Capital stock records; retention periods.  
Rule 11. The following capital stock records shall be retained for the periods listed:  
(a) Capital stock ledgers or other records  
showing the same information  
6 years after the stockholder’s account is  
closed. For the purpose of this subdivision, a  
stockholder’s account may be treated as closed  
Page 3  
account at the time that such stock- holder  
ceases to be a holder of record of the particular  
class of stock of the company, and the 6-year  
retention period prescribed herein shall run  
from that date. If such person subsequently  
acquires shares of capital stock of the company  
and thus again becomes a stockholder of the  
company, the record of such acquisition shall  
be treated as a new stockholder account.  
(b) Capital stock subscription accounts,  
warrants, requests for allotments, and other  
essential papers related thereto.  
2 years after settlement.  
(c) Stubs or similar records of capital  
stock certificate issuance where not used as  
capital stock ledger record.  
6 years after cancellation of certificate. If  
this record serves the purpose of a capital stock  
ledger, subdivision (a) is applicable.  
(d) Stock transfer registers or sheets or  
similar records.  
6 years after last entry on page or sheet of  
the record.  
(e) Papers pertaining to, or supporting  
transfers of, capital stock as follows:  
(i) Papers that are recorded officially in a  
court or in the office of some other public  
recording authority; and other papers presented  
by any bank or trust company requesting  
transfers in its capacity as a fiduciary.  
Destroy at option or return to stockholder.  
(ii) Any other papers not described in  
subdivision (e) (i) of this rule.  
3 years from the date of transfer.  
(f) Canceled capital stock certificates  
6 years after cancellation. If this record  
where not used as capital stock ledger records. serves the purpose of a capital stock ledger,  
subdivision (a) is applicable.  
(g) Change of address notices of  
stockholders.  
Destroy at option after changes are  
recorded.  
(h) Bonds of indemnity and affidavits  
covering issuances of stock certificates to  
replace lost certificates.  
6 years after expiration of bonds.  
(i) Letters, notices, reports, statements,  
and other communications distributed to all  
Page 4  
stockholders of a particular class as follows:  
(i) Formal communications addressed to  
all stockholders of a particular class, including  
annual reports to stockholders, notices of  
annual and special meetings of stockholders,  
and other notices, letters, reports, or statements  
relating to corporate or stockholder actions.  
Life of the corporation.  
(ii) Interim reports of operations, speeches  
of corporate officers and notices of change of  
corporate address or telephone numbers and  
similar information.  
6 years after the date thereof.  
(j) Dividend registers lists or similar  
records.  
6 years.  
(k) Paid dividend checks.  
6 years.  
(l) Third party dividend orders.  
6 years after rescission order.  
History: 1979 AC; 1980 AACS.  
R 460.2512 Debt security records; retention periods.  
Rule 12. The following debt security records shall be retained for the periods listed:  
(a) Registered bond and debenture  
ledgers.  
(b) Bond and debenture subscription  
accounts, warrants, subscription notices,  
requests for allotment, and essential papers  
related thereto.  
3 years after redemption.  
3 years after settlement.  
(c) Stubs or similar records of bond and  
debenture certificates issued.  
3 years after redemption.  
Page 5  
(d) Papers pertaining to, or supporting  
transfers of, registered bonds and debentures as  
follows:  
(i) Papers that are recorded officially in a  
court or in the office of some other public  
recording authority; and other papers presented  
by any bank or trust company requesting  
transfers in its capacity as a fiduciary.  
Destroy at option or return to holders of the  
bonds or debentures.  
(ii) Any other papers not described in  
subdivision (d) (i) of this rule.  
3 years after transfer.  
(e) Records of bond and debenture the  
interest coupons paid and unpaid.  
Destroy at option in compliance with note  
under subdivision (h).  
(f) Canceled bonds and debentures the and  
paid interest coupons pertaining thereto.  
Destroy at option in compliance with note  
under subdivision (h).  
(g) Trust indentures, loan agreements, or  
other contracts or agreements securing debt  
securities issued. (If such papers or documents  
are included among the records covered by rule  
13, this instruction shall not apply).  
6 years after redemption.  
(h) Copies of reports, statements, letters,  
or memoranda filed with a trustee or trustees  
pursuant to provisions of a trust indenture or  
other security instrument or agreement  
securing debt securities issued.  
6 years after redemption. Destroy at option  
if the trustee or trustees under such identure or  
security instrument are national banks,  
members of the federal reserve system, or  
subsidiaries of any such national bank or  
federal reserve system member bank and if the  
trustee or trustees have certified to the  
company that copies of all such documents will  
be available in the offices of the trustee or  
trustees for inspection at any time before  
redemption by holders of debt securities to  
which such documents relate and for inspection  
by any federal or state regulatory authority  
prior to redemption and for an additional  
period of 6 years after redemption.  
Note: Canceled bonds and debentures and  
paid interest coupons pertaining thereto may be  
destroyed if a certificate of destruction that  
gives a full descriptive reference to the  
documents destroyed is made by the person or  
persons authorized to perform such destruction  
Page 6  
and is retained by the company for the period  
herein prescribed. The certificate of  
destruction that evidences the destruction of  
paid interest coupons pertaining to bonds or  
debentures need not contain a listing of the  
bond or debenture serial numbers pertaining to  
such paid interest coupons. When documents  
represent debt secured by mortgage, the  
certificate of destruction shall also be  
authorized by a representative of the trustee or  
trustees acting in conjunction with the person  
or persons destroying the documents or shall  
have the trustee’s or trustees’ acceptance  
thereon. The certificate of destruction may be  
destroyed 6 years after the payment and  
discharge of the bonds or debendures or  
interest coupons described in such certificate.  
(i) Paid or canceled debt securities  
evidencing temporary borrowings.  
3 years after payment or cancellation if  
other records of issuance and payment or  
cancellation are maintained.  
(j) Paid interest checks.  
6 years.  
The terms “bonds” and “debentures,” as  
used in subdivisions (a) to (f) of this rule,  
include all debt securities, such as bonds,  
debentures, or notes other than debt securities  
which evidence temporary borrowings and  
which are expected to be repaid out of the  
proceeds of the sale of longer term securities.  
Typical of such temporary debt securities as  
described in subdivision (i) are notes issued to  
banks evidencing temporary working capital  
and construction and gas storage loans.  
History: 1979 AC; 1980 AACS.  
R 460.2513 Authorization records from regulatory bodies for issuance of securities;  
retention periods.  
Rule 13. The following authorization records from regulatory bodies for issuance of  
securities shall be retained for the periods listed:  
Page 7  
(a) Copies of applications to regulatory  
25 years or until all securities covered are  
bodies for authority to issue stocks, bonds, and retired, whichever is shorter. If a retention  
other securities, including copies of exhibits in period is prescribed elsewhere in the schedule  
support of such applications.  
with respect to any document which is  
included as an exhibit to any filing retained  
pursuant to the requirements of this  
subdivision, the company need retain only 1  
copy of such document in its files if  
appropriate cross-references are established.  
(b) Official copies of opinions and orders  
of regulatory bodies granting authority to issue  
securities.  
Until securities covered are retired.  
Until securities covered are retired.  
(c) Reports filed with regulatory bodies in  
compliance with authorizations to issue  
securities. File copies of such reports and  
supporting papers.  
History: 1979 AC; 1980 AACS.  
R 460.2514 Copies of registration statements and other data filed with the securities and  
exchange commission; retention periods.  
Rule 14. The following copies of registration statements and other data filed with the  
securities and exchange commission shall be retained for the periods listed:  
(a) Copies of registration statements and  
other data in connection with offerings of  
25 years or until all securities covered are  
retired, whichever is shorter. If a retention  
securities for sale to the public or the listing of period is prescribed elsewhere in the schedule  
securities on exchanges, including supporting  
papers.  
with respect to any document which is  
included as an exhibit to any filing retained  
pursuant to the requirements of this  
subdivision, the company need retain only 1  
copy of such document in its files, if  
appropriate cross-references are established.  
(b) Copies of periodic reports and  
supporting papers filed in compliance with  
either the securities act of 1933 or the  
securities exchange act of 1934.  
25 years. If a retention period is prescribed  
elsewhere in the schedule with respect to any  
document which is included as an exhibit to  
any filing retained pursuant to the requirements  
of this subdivision, the the company need  
retain only 1 copy of such document in its  
files, if appropriate cross- references are  
established.  
Page 8  
History: 1979 AC; 1980 AACS.  
R 460.2515 Proxies and voting lists; retention periods.  
Rule 15. Proxies and voting lists shall be retained for the periods listed:  
(a) Proxies of holders of voting securities.  
1 year.  
1 year.  
(b) Lists of holders of voting securities  
represented at meetings.  
History: 1979 AC; 1980 AACS.  
R 460.2516 Minute books; retention period.  
Rule 16. Minute books of stockholders’, directors’, and directors’ committee meetings shall  
be retained for the life of the corporation.  
History: 1979 AC; 1980 AACS.  
R 460.2517 Title papers, charters, franchises, licenses, formal orders; retention periods.  
Rule 17. The following documents shall be retained for the periods listed:  
(a) Deeds and other title papers, including  
abstracts of title and supporting data.  
6 years after property is disposed of, unless  
surrendered to transferee.  
(b) Corporate charters or certificates of  
incorporation.  
Life of the corporation.  
Life of the corporation.  
25 years.  
(c) Franchises and certificates authorizing  
operation as a public utility.  
(d) Licenses, including amendments  
thereof, granted by federal or state authorities  
for construction and operation of utility plant.  
(e) Copies of formal orders of regulatory  
commissions served upon the uti1ity.  
Life of the corporation.  
History: 1979 AC; 1980 AACS.  
R 460.2518 Permits; retention periods.  
Rule 18. The following permit records shall be retained for the periods listed:  
Page 9  
(a) Permits and granted applications for  
the use of facilities of others.  
6 years after expiration or cancellation.  
6 years after expiration or cancellation.  
Destroy at option.  
(b) Copies of permits and applications  
granted others for the use of the utility’s  
facilities.  
(c) Applications for the use of facilities  
not granted and copies of such applications.  
(d) Permits of a temporary nature from  
municipalities or others to perform specific  
work, such as permits to open streets.  
Destroy at option.  
History: 1979 AC; 1980 AACS.  
R 460.2519 Contracts and agreements; retention periods.  
Rule 19. Except as provided elsewhere in these rules, the following contract and agreement  
records shall be retained for the periods listed:  
(a) Service contracts, such as for management,  
accounting, and financial services including  
related memoranda and revisions.  
See R 460.2522(b)(i) if they affect cost of  
plant; otherwise, 6 years after expiration or  
cancellation or until the conclusion of any  
contract disputes or governmental proceedings  
pertaining to these contracts, whichever is  
later.  
(b) Contracts with other utilities for the  
purchase, sale, or interchange of product,  
including related memoranda or revisions.  
6 years after expiration or cancellation or  
until the conclusion of any contract disputes or  
governmental proceedings pertaining to these  
contracts, whichever is later.  
(c) Leases pertaining to rentals of property to  
or from others.  
6 years after expiration or cancellation or  
until the conclusion of any contract disputes or  
governmental proceedings pertaining to these  
contracts, whichever is later.  
(d) Contracts and agreements with individual  
6 years after expiration or cancellation or  
employees, labor unions, company unions, and until the conclusion of any contract disputes or  
other employee organizations relative to wage governmental proceedings pertaining to these  
rates, hours, and similar matters.  
contracts, whichever is later.  
(e) Contracts, agreements, and other essential  
records necessary to the carrying out of the  
functions of an employee’s stock purchase or  
other type of employees’ saving plan.  
6 years after expiration or cancellation.  
Page 10  
(f) Memoranda essential to clarifying or  
explaining provisions of contracts listed in  
subdivisions (a) to (e) of this rule.  
For same periods as contracts to which they  
relate.  
(g) Card or book records of contracts leases,  
and agreements made, which show dates of  
expirations, dates of renewals, memoranda of  
receipts, and payments under such contracts,  
leases, and agreements.  
For same periods as contracts to which they  
relate.  
(h) Contracts or agreements for the acquisition  
or disposal of investments, excluding  
temporary cash investments.  
25 years after disposal.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2520 General and subsidiary ledgers; retention periods.  
Rule 20. The following ledger records shall be retained for the periods listed:  
(a) General ledgers.  
10 years.  
10 years.  
(b) Ledgers subsidiary or auxiliary to general  
ledgers, except ledgers provided for elsewhere  
in these rules.  
(c) Indexes to general ledgers.  
10 years.  
10 years.  
(d) Indexes to subsidiary ledgers except ledgers  
provided for elsewhere in these rules.  
(e) Trial balance sheets of general and  
subsidiary ledgers.  
2 years.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2521 Journals; retention period.  
Rule 21. General and subsidiary journals, including departmental and divisional journals,  
shall be retained for a period of 10 years.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2522 Journal vouchers and entries; retention periods.  
Rule 22. The following journal voucher and entry records shall be retained for the periods  
listed:  
Page 11  
(a) General, departmental, divisional, and petty  
journal vouchers.  
25 years.  
(b) Materials and supplies disbursement, labor  
distribution, and other detail summarization  
and distribution records that support journal  
vouchers or journal entries as follows:  
(i) Charging plant accounts.  
6 years, if accounting adjustments resulting  
from reclassification and original cost studies  
have been approved by the regulatory  
commissions having jurisdiction and if  
continuing plant inventory records are  
maintained or unitization of construction costs  
appear in work orders; otherwise 25 years. For  
licensed projects, time tickets, and material  
issued and material returned tickets may be  
destroyed at option if the basic information  
contained in the accounts is transcribed to  
other records and if such other records are  
retained pursuant to this instruction. Basic  
information regarding time tickets includes, at  
a minimum, for the purpose of this instruction,  
hours worked and the distribution of time to  
the proper job or account.  
(ii) Charging all other accounts.  
6 years.  
(c) Papers forming part of, or necessary to  
explain, journal vouchers or journal entries,  
except as covered in subdivision (b) of this  
rule.  
25 years.  
(d) Schedules for recurring journal entries.  
(e) Lists of standard journal entry numbers.  
Destroy when superseded.  
Destroy when superseded.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2523 Cash books; retention periods.  
Rule 23. The following cash book records shall be retained for the periods listed:  
(a) Treasurer and auditor general cash  
books.  
3 years.  
Page 12  
(b) Cash books subsidiary or auxiliary to  
general cash books, except those showing only  
collections from customers.  
3 years.  
(c) Subsidiary cash records showing only  
customer collections.  
3 years.  
3 years.  
(d) Other cash records of a memorandum  
nature.  
History: 1979 AC; 1980 AACS.  
R 460.2524 Vouchers and voucher registers; retention periods.  
Rule 24. (1) The following voucher records shall be retained for the periods listed:  
(a) Paid and canceled vouchers (1 copy)  
6 years, as specified in R 460.2522(b)(i)  
analysis sheets showing detailed distribution of and (ii), except that those relating to the  
charges on individual vouchers and other  
supporting papers.  
construction of licensed projects, additions or  
betterment of those projects, or the  
amortization reserve applicable to those  
projects, for which the commission has not  
determined the actual legitimate original cost,  
shall be retained until such cost has been  
determined.  
(b) Original bills and invoices for materials and  
services paid by vouchers.  
6 years as specified in R 460.2522(b)(i)  
and (ii), except that those relating to the  
construction of licensed projects, additions or  
betterment of those projects, or the  
amortization reserve applicable to those  
projects, for which the commission has not  
determined the actual legitimate original cost,  
shall be retained until this cost has been  
determined.  
(c) Paid checks and receipts for payments by  
voucher or otherwise.  
6 years.  
(d) Authorization for the payment of specific  
vouchers.  
6 years.  
(e) Lists of unaudited bills (accounts payable),  
lists of vouchers transmitted, and memoranda  
regarding changes in unaudited bills.  
Destroy at option.  
(f) Voucher indexes.  
Destroy at option.  
Page 13  
(2) Voucher registers or similar records shall be retained for a period of 6, as specified in R  
460.2522(b)(i) and (ii).  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2525 Rescinded.  
History: 1979 AC; 1980 AACS.  
R 460.2526 Accounts receivable; retention periods.  
Rule 26. The following accounts receivable records shall be retained for the periods listed  
(see rules 53 and 54 for accounts with customers for utility service and merchandise sales):  
(a) Records of accounts receivable  
pertaining to sales of utility plant.  
3 years after settlement.  
3 years after settlement.  
(b) Record or register of accounts  
receivable and indexes thereto and summaries  
of distribution.  
(c) Accounting department copies of  
invoices issued and supporting papers which  
do not accompany the original invoices and  
authorizations for charges, including  
supporting papers.  
3 years after settlement.  
(d) Periodic statements of unsettled  
accounts, except trial balances.  
Destroy at option.  
Destroy at option.  
(e) Schedule of invoices to be issued.  
History: 1979 AC; 1980 AACS.  
R 460.2527 Records of securities; retention period.  
Rule 27. Records of securities owned, in treasury, or with custodians shall be retained for a  
period of 6 years after the disposal of investment.  
History: 1979 AC; 1980 AACS.  
R 460.2528 Insurance records; retention periods.  
Rule 28. The following insurance records shall be retained for the periods listed:  
Page 14  
(a) Records of insurance policies which  
are in force and which show coverage,  
premiums paid, and expiration dates.  
Destroy at option after expiration of such  
policies.  
(b) Insurance policies.  
Destroy at option after expiration of  
policies.  
(c) Records of amounts recovered from  
6 years, except those relating to the  
insurance companies in connection with losses construction of licensed projects, additions or  
and of claims against insurance companies,  
including reports of losses and supporting  
papers.  
betterment thereto, or the amortization reserve  
applicable thereto, for which the commission  
has not determined the actual legitimate  
original cost, shall be retained until such cost  
has been determined.  
(d) Inspector reports and records of the  
condition of property.  
Until superseded.  
Until superseded.  
Destroy at option.  
(e) Insurance maps of property and  
structures erected thereon.  
(f) Records and statements relating to  
insurance requirements.  
History: 1979 AC; 1980 AACS.  
R 460.2529 Tax records; retention periods.  
Rule 29. The following tax records shall be retained for the periods listed:  
(a) Copies of schedules, returns, and  
supporting working papers to taxing authorities  
and records of appeals of the following:  
(i) Federal income, excess profits,  
undistributed income, and capital stock taxes.  
(ii) State income taxes and state or local  
property taxes.  
7 years after settlement.  
7 years after settlement.  
(iii) Other taxes.  
2 years after settlement.  
7 years after allocation.  
(iv) Schedule of allocation of consolidated  
federal income taxes to subsidiary companies.  
(v) Records of annual determinations of  
deferred taxes on income, annual determina-  
tions of accounting adjustments for “reserve  
deferrals” of deferred taxes on income,  
together with basic computations and records  
of annual plant additions and retirements and  
6 years after absorption of deferred credits.  
Page 15  
adjustments on which deferred tax accounting  
entries are based. For the purposes of this rule,  
“deferred taxes” and “deferred tax accounting”  
embrace provisions for “future taxes on  
income,” “prepaid taxes on income, or any  
other accounting procedure which attributes a  
tax on income to a year or years other than that  
of the specific year’s tax return determining the  
tax liability.  
(b) Tax bills from taxing authorities and  
receipts for payment.  
See rule 24 (1)(b).  
6 years.  
(c) Summaries of taxes paid by classes of  
taxes and by location.  
(d) Summaries of taxes paid by taxing  
districts.  
6 years.  
(e) Restatements of schedules of taxes  
paid after giving effect to refunds and  
additional assessments.  
6 years.  
History: 1979 AC; 1980 AACS.  
R 460.2530 Accountants and auditor reports; retention periods.  
Rule 30. The following accountant and auditor reports shall be retained for the periods  
listed:  
(a) Reports of examinations and audits by  
7 years after date of report or commission  
audit, whichever comes last.  
accountants and auditors not in the regular  
employ of the utility, including reports of  
public accounting firms and regulatory  
commission accountants.  
(b) Internal audit reports and working  
papers.  
3 years.  
History: 1979 AC; 1980 AACS.  
R 460.2531 Automatic data processing record; retention periods.  
Rule 31. (1) The following automatic data processing records shall be retained for the  
periods listed:  
Page 16  
(a) Media used as intermediate records or steps  
in data processing for assembling data to be  
posted to the records of the company or used in  
a report or study.  
Destroy at option.  
(b) Program documentation and revisions to  
this documentation.  
Retain as long as it represents an active  
viable program or for periods prescribed for  
related output data, whichever is shorter.  
(2) Original source data used as input for data processing and data processing report  
printouts shall be retained for the applicable periods prescribed elsewhere in the schedule.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2532 Plant ledgers; retention periods.  
Rule 32. The following plant ledgers and records shall be retained for the periods listed:  
(a) Ledgers of utility plant accounts, including  
land and other detailed ledgers that show the  
cost of utility plant by classes.  
25 years.  
(b) Continuing plant inventory ledger, book, or  
card records that show the description,  
25 years after the plant is retired if  
mortality data are retained. For depreciation  
location, quantity cost, and similar information purposes, life or mortality study data shall be  
of physical units, or items, of utility plant  
retained for the life of the corporation.  
owned.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2533 Construction ledgers, work orders, and supplemental records; retention  
periods.  
Rule 33. The following construction work in progress ledgers, work orders, and  
supplemental records shall be retained for the periods listed:  
(a) Construction work in progress ledgers.  
5 years after clearance to the plant account  
if continuing plant inventory records are  
maintained; otherwise, 5 years after the plant is  
retired.  
(b) Work order sheets that show entries for  
labor, materials, and other charges for utility  
plant additions, and entries closing the work  
5 years after clearance to the plant account  
if continuing plant inventory records are  
maintained; otherwise, 5 years after the plant is  
orders for utility plant in service at completion. retired.  
Page 17  
(c) Authorizations for expenditures for  
additions to utility plant, including memoranda  
that show the detailed estimates of cost and the  
basis for that estimated cost. Original and  
revised or subsequent authorizations shall be  
included.  
5 years.  
(d) Requisitions and registers of authorizations  
for utility plant expenditures.  
5 years.  
5 years.  
(e) Completion or performance reports that  
show the comparison between authorized  
estimates and actual expenditures for utility  
plant additions.  
(f) Analysis or cost reports that show quantities  
of materials used, unit costs, number of man-  
hours, and similar information in connection  
with completed construction projects.  
5 years after clearance to the plant account  
if continuing plant inventory records are  
maintained; otherwise, 6 years after the plant is  
retired.  
(g) Records and reports that pertain to the  
progress of construction work, the order in  
which jobs are to be completed, and similar  
records that do not form a basis of entries to  
the accounts.  
Destroy at option.  
(h) Records of gas acreage owned, leased, or  
optioned; lease records; well-drilling logs and  
well-construction records; and geological and  
photographic maps of field.  
1 year after the facility or relevant  
production area is abandoned.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2534 Retirement ledgers, work orders, and supplemental records; retention  
periods.  
Rule 34. The following retirement work in progress ledgers, work orders, and supplemental  
records shall be retained for the periods listed:  
(a) Work order sheets that have the entries for  
5 years after the plant is retired if mortality  
removal costs, materials recovered, and credits data are retained.  
to utility plant accounts for cost of plant retired  
posted to them.  
(b) Authorization for retirement of utility plant,  
including memoranda that show the basis for  
the determination of the cost of plant to be  
retired and estimates of salvage and removal  
costs.  
5 years after clearance to the plant account  
if continuing plant inventory records are  
maintained; otherwise, 5 years after the plant is  
retired, if mortality data are retained.  
Page 18  
(c) Registers of retirement work orders.  
5 years.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2535 Additional plant account records; retention periods.  
Rule 35. Summary sheets, distribution sheets, reports, statements, and papers that directly  
support debits and credits to utility plant accounts that are not covered by construction or  
retirement work orders and their supporting records shall be retained for a period of 10 years  
after clearance to the plant account if continuing plant inventory records are maintained;  
otherwise, 6 years after plant is retired.  
History: 1979 AC; 1980 AACS.  
R 460.2536 Appraisals and valuations; retention period.  
Rule 36. Appraisals and valuations made by the company of its properties or investments or  
of the properties or investments of any associated companies, including all records essential  
thereto, shall be retained for a period of 3 years after disposition, termination of lease, or write-  
off of the property investment.  
History: 1979 AC; 1980 AACS.  
R 460.2537 Maps; retention period.  
Rule 37. Maps and map reproductions that show the location and physical characteristics of  
production, transmission, and distribution systems of the utility shall be retained until the map is  
superseded or until 6 years after plant is retired, if mortality data are retained.  
History: 1979 AC; 1980 AACS.  
R 460.2538 Construction project engineering records; retention period.  
Rule 38. (1) If a construction project is wholly or partially completed, maps or map  
reproductions, diagrams, profiles, plans, photographs, records of engineering studies, and similar  
records in connection with the project shall be retained until these records are superseded or until  
6 years after plant is retired, if mortality data are retained.  
(2) If construction of the project does not result, the records may be destroyed at option after  
completely accounting for all expenses incurred.  
History: 1979 AC; 1980 AACS.  
R 460.2539 Utility plant contracts and agreements; retention periods.  
Rule 39. The following contracts and other agreements that relate to utility plant shall be  
retained for the periods listed:  
Page 19  
(a) Contracts relating to the acquisition or  
sale of plant.  
6 years after plant is retired.  
6 years after plant is retired.  
(b) Contracts and other agreements that  
relate to services performed in connection with  
the construction of utility plant, including  
contracts for the construction of plant by others  
for the utility and contracts for supervision and  
engineering relating to construction work.  
History: 1979 AC; 1980 AACS.  
R 460.2540 Account reclassification records; retention period.  
Rule 40. Records that pertain to reclassifications of utility plant accounts to conform to  
prescribed systems of accounts, including supporting papers that show the basis for such  
reclassifications shall be retained for a period of 6 years. (See rule 22 (b) (i)).  
History: 1979 AC; 1980 AACS.  
R 460.2541 Depreciation and depletion reserve records; retention periods.  
Rule 41. The following records of reserve for depreciation and depletion of utility plant  
shall be retained for the periods listed:  
(a) Detailed records or analysis sheets that  
segregate the depreciation reserve according to  
functional classification of plant.  
25 years.  
(b) Records that support computation of  
depreciation and depletion expense of utility  
plant, including such data as life and salvage  
studies.  
25 years.  
History: 1979 AC; 1980 AACS.  
R 460.2542 Statements of funds and deposits: retention periods.  
Rule 42. The following fund and deposit statement records shall be retained for the periods  
listed:  
(a) Summaries and periodic statements of  
cash balances on hand and with depositories.  
Destroy at option.  
Page 20  
(b) Statement of manager and agent cash  
balances on hand and with depositories.  
Destroy at option.  
Destroy at option.  
(c) Authorizations for and statements of  
the transfer of funds from one depository to  
another.  
(d) Requisitions and receipts for funds  
furnished to managers, agents, and others.  
Destroy at option after funds have been  
returned or accounted for.  
(e) Records of fidelity bonds of  
employees and others responsible for funds of  
the utility.  
Until liability of bonding company has  
expired.  
(f) Reports and estimates of funds  
Destroy at option.  
required for general and special purposes.  
History: 1979 AC; 1980 AACS.  
R 460.2543 Deposit records; retention periods.  
Rule 43. The following deposit records shall be retained for the periods listed:  
(a) Bank deposit books.  
1 year.  
(b) Copies of bank deposit slips.  
1 year.  
(c) Advice of deposits made when information  
about the deposits is shown on other records  
that are retained.  
Destroy at option.  
(d) Statements from depositories that show the  
details of funds received, disbursed, and  
transferred and balances on deposits.  
Destroy at option.  
(e) Bank reconcilement papers.  
1 year.  
1 year.  
3 years.  
(f) Statements from banks of interest credits.  
(g) Check stubs, registers, or other records of  
checks issued.  
(h) Correspondence and memoranda that relate  
3 years or destroy at option after recovery  
to the stopping of payment of bank checks and of the check(s).  
to the issuance of duplicate checks.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
Page 21  
R 460.2544 Receipt and disbursement records; retention periods.  
Rule 44. The following receipt and disbursement records shall be retained for the periods  
listed:  
(a) Daily or other periodic statements of  
receipts or disbursements of funds.  
2 years.  
2 years.  
(b) Records or periodic statements of  
outstanding vouchers, checks, drafts, issued  
and not presented.  
(c) Reports of associates that show  
working fund transactions and summaries  
thereof.  
Destroy at option.  
Destroy at option.  
(d) Reports of revenue collections by field  
cashiers and pay stations.  
History: 1979 AC; 1980 AACS.  
R 460.2545 Customer service applications and contracts; retention periods.  
Rule 45. The following customer service applications and contracts shall be retained for the  
periods listed:  
(a) Applications for utility service for which  
contracts have been executed.  
Destroy at option.  
1 year.  
(b) Applications for utility service used in  
place of contracts.  
(c) Contracts and card files, or other records  
thereof, with customers for utility service.  
1 year after expiration or cancellation. If  
the contracts are with other utilities for the  
purchase, sale or interchange of product, R  
460.2519(b) applies.  
(d) Applications for utility service that were  
withdrawn by the applicant or not granted by  
the utility.  
1 year.  
(e) Contracts or sales agreements with  
customers and others for the sale of  
merchandise and appliances.  
1 year after sales agreement is discharged.  
Page 22  
(f) Contracts for the lease of equipment to  
customers, including receipts for this  
equipment.  
1 year after expiration of contract or return  
of equipment.  
(g) Applications and contracts for extensions  
covered by refundable deposits or guarantees  
of revenue and records that pertain to such  
contracts.  
1 year after entire amount is refunded.  
6 years after expiration.  
(h) Applications and contracts for extensions  
for which donations or contributions are made  
by customers or other individuals.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2546 Rate schedules; retention periods.  
Rule 46. The following rate schedule records shall be retained for the periods listed:  
(a) General files of published rate sheets and  
schedules of utility service, including  
schedules suspended or superseded.  
6 years.  
(b) Regional or local office copies of rate  
sheets and schedules of utility service.  
1 year after expiration or cancellation.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2547 Customer guarantee deposit records; retention periods.  
Rule 47. The following customer guarantee deposit records shall be retained for the periods  
listed:  
(a) Customer deposit ledgers or card  
records.  
(b) Customer deposit certificate books.  
6 years after refund.  
6 years after refund.  
6 years after refund.  
6 years after refund.  
(c) Receipts for refunded customer  
deposits.  
(d) Receipts for interest on customer  
deposits.  
History: 1979 AC; 1980 AACS.  
R 460.2548 Meter reading sheets and records; retention periods.  
Page 23  
Rule 48. The following meter reading sheets and records shall be retained for the periods  
listed:  
(a) Superseded meter reading sheets.  
2 years or as necessary to comply with  
service rules regarding refunds on fast meters.  
(b) Meter reread sheets (special readings  
to check high or low consumption).  
(c) Customer reading cards.  
1 year.  
1 year.  
(d) Connection and disconnection orders.  
(e) Superseded indexes to meter books.  
1 year.  
Destroy at option.  
(f) Mark sensed meter reading cards.  
Note: If a gas utility collects rates authorized  
by this commission based on increased  
Destroy at option after transferring data to  
other records.  
supplier rates collected under bond under  
authority of the federal energy regulatory  
commission, such utility shall maintain  
sufficient gas consumption records to enable  
the calculation of refunds to individual  
customers as may be ordered by the Michigan  
public service commission. This requirement  
shall continue in effect until final action by the  
federal energy regulatory commission or the  
final decree of the court, if appealed thereto,  
and until such time as the Michigan public  
service commission enters its order authorizing  
appropriate refunds if such be the case.  
History: 1979 AC; 1980 AACS.  
R 460.2549 Charts and demand meter record cards; retention period.  
Rule 49. Maximum demand, pressure, temperature, and specific gravity charts and demand  
meter record cards shall be retained for a period of 1 year, except that if charts are exchanged  
with the customer and the basic chart information is transferred to another record, the charts need  
only be retained 6 months if the record containing the basic data is retained 1 year.  
History: 1979 AC; 1980 AACS.  
R 460.2550 Miscellaneous billing data; retention periods.  
Rule 50. The following billing data shall be retained for the periods listed:  
Page 24  
(a) Billing department copies of contracts  
with customers (in addition to contracts in  
general files).  
(b) Service and inspection orders from  
which customers are charged and sundry  
charge advices.  
Destroy at option.  
1 year.  
(c) Authorizations for charges under  
utility service contracts.  
(d) Standard billing sheets or schedules  
that show computed bills of varying  
consumption according to rates.  
1 year after expiration of contract.  
Destroy at option.  
History: 1979 AC; 1980 AACS.  
R 460.2551 Revenue summaries; retention. periods.  
Rule 51. The following revenue summaries shall be retained for the periods listed:  
(a) Summaries of monthly operating  
revenues according to classes of service for the  
entire utility.  
6 years.  
6 years.  
(b) Summaries of monthly operating  
revenues according to classes of service by  
towns, districts, or regions, including  
summaries of forfeited discounts and penalties.  
History: 1979 AC; 1980 AACS.  
R 460.2552 Customer ledgers and records used in place of ledgers; retention periods.  
Rule 52. The following customer ledgers and other records used in place of ledgers shall be  
retained for the periods listed:  
(a) Customer ledgers.  
2 years or as necessary to comply with  
service rules regarding refunds on fast meters.  
(b) Records used in place of customer  
ledgers, such as bill summaries, registers, and  
bill stubs.  
2 years or as necessary to comply with  
service rules regarding refunds on fast meters.  
(c) Copies of large bills:  
(i) If details are transcribed to ledgers  
covered by subdivision (a) of this rule.  
Destroy at option.  
Page 25  
(ii) If details are not transcribed to  
ledgers.  
(d) Trial balances of ledgers referred to in  
this rule.  
2 years.  
1 year.  
(e) Indexes to customer accounts.  
(f) Change of address notices.  
2 years.  
Destroy at option.  
2 years.  
(g) Cards and other records relating to  
forfeited discounts.  
History: 1979 AC; 1980 AACS.  
R 460.2553 Merchandise sales accounting and collecting records; retention periods,  
Rule 53. The following merchandise sales accounting and collecting records shall be  
retained for the periods listed:  
(a) Merchandise sales tickets (duplicates)  
and charge slips for work done.  
Destroy at option after annual audit and 6  
months after account is settled.  
(b) Merchandise sales journals or registers  
and summaries of sales.  
3 years.  
(c) Merchandise ledgers and installment  
records.  
1 year after completion of payments.  
(d) Merchandise sales returns and  
adjustment tickets.  
Destroy at option after annual audit and 6  
months after account is settled.  
(e) Cashier stubs for merchandise  
collections.  
(f) Cashier periodic reports and statements  
of collections on merchandise accounts.  
1 year.  
1 year.  
(g) Records of monthly statements to  
customers.  
Destroy at option.  
1 year.  
(h) Reports relating to the status of  
merchandise accounts receivable.  
(i) Job orders and supporting details of  
charges to customers for work done.  
3 years.  
Page 26  
(j) Indexes and trial balances of  
merchandise ledgers.  
1 year.  
History: 1979 AC; 1980 AACS.  
R 460.2554 Collection reports and records; retention periods.  
Rule 54. The following collection reports and records shall be retained for the periods  
listed:  
(a) Periodic reports, lists, and summaries  
Destroy at option.  
6 months.  
of collections of operating revenues by  
collectors, agents, and local, regional, or  
district offices. (See rule 44(d)).  
(b) Bill stubs, copies of bills, collection  
slips, and other records which pertain to  
collections that are summarized or detailed in  
daily or periodic cash reports.  
(c) Memorandum records of remittances  
from local or branch offices.  
6 months.  
Note: See rule 43 pertaining to deposits of  
cash with banks. Rule 43 applies to all bank  
accounts whether at general, local, or regional  
offices.  
History: 1979 AC; 1980 AACS.  
R 460.2555 Customer account adjustments; retention periods.  
Rule 55. The following customer account adjustment records shall be retained for the  
periods listed:  
(a) Detailed records that pertain to adjust-  
1 year.  
1 year.  
ments of customer accounts for overcharges,  
undercharges, and other errors, the results of  
which have been transcribed to other records.  
(b) Detailed records of high bill  
complaints whether or not the complaints  
resulted in adjustments to customer accounts.  
Page 27  
History: 1979 AC; 1980 AACS.  
R 460.2556 Uncollectible accounts and customer credit records; retention periods.  
Rule 56. The following uncollectible account and customer credit records shall be retained  
for the periods listed:  
(a) Records of ratings, credit  
classifications, and investigations of  
customers.  
Destroy at option.  
For period legally collectible.  
1 year.  
(b) Ledger accounts and supporting  
details of customer accounts that are  
considered to be uncollectible.  
(c) Reports and statements that show the  
age and status of customer accounts.  
(d) Data on unpaid final bills.  
1 year.  
(e) Authorization for writing off customer  
accounts.  
3 years.  
History: 1979 AC; 1980 AACS.  
R 460.2557 Payroll records; retention periods.  
Rule 57. The following payroll records shall be retained for the periods listed:  
(a) Payroll sheets or registers of payments  
of salaries and wages to individual officers and  
employees. (See subdivision (j) for pension or  
annuity payrolls and rule 33(a) for construction  
payrolls).  
6 years.  
(b) Records that show the distribution of  
salaries and wages paid to officers and  
employees for each monthly, semi-monthly, or  
weekly payroll period and summaries or  
recapitulation statements of such distribution.  
See rule 22(b).  
See rule 22(b).  
(c) Time tickets, time sheets, time books,  
time cards, worker reports, and other records  
that show hours worked, description of work,  
and accounts to be charged.  
Page 28  
(d) Paid checks, receipts for wages paid in  
cash, and other evidences of payments for  
services rendered by employees.  
3 years.  
3 years.  
(e) Applications and authorizations for  
changes in wage and salary rates, summaries  
and reports of changes in payrolls, and similar  
records.  
(f) Applications for payroll changes not  
authorized.  
Destroy at option.  
3 years.  
(g) Payroll authorizations and records of  
authorized positions.  
(h) Records of deductions from payrolls.  
Destroy at option.  
Destroy at option.  
(i) Comparative or analytical statements  
of payrolls.  
(j) Pension or annuity payrolls.  
(k) Pension paychecks.  
6 years.  
3 years.  
(l) Employee individual earning records.  
6 years after termination of employment.  
History: 1979 AC; 1980 AACS.  
R 460.2558 Assignments, attachments, and garnishments; retention period.  
Rule 58. Records of assignments, attachments, and garnishments of employee salaries,  
including files of notices pertaining thereto, may be destroyed at option. Minors’ salary releases  
may also be destroyed at option.  
History: 1979 AC; 1980 AACS.  
R 460.2559 Personnel records; retention periods.  
Rule 59. The following personnel records shall be retained for the periods listed:  
(a) Employee service records, length of  
service, and other pertinent data.  
3 years after termination of employment.  
Destroy at option.  
(b) Applications for employment, requests  
for medical examination, medical examiner’s  
Page 29  
report, photographs and other identification  
records, and other miscellaneous records  
pertaining to the hiring of employees.  
History: 1979 AC; 1980 AACS.  
R 460.2560 Welfare and pension records; retention periods.  
Rule 60. The following employee welfare and pension records shall be retained for the  
periods listed:  
(a) Records pertaining to employee  
recreational, educational, and hospital benefits,  
accident prevention, and similar activities.  
Destroy at option.  
(b) Detailed records that show  
25 years.  
computations of accruals for pension liabilities.  
History: 1979 AC; 1980 AACS.  
R 460.2561 Instructions; retention periods.  
Rule 61. The following instructions to employees and others shall be retained for the  
periods listed:  
(a) Bulletins or memoranda of general  
10 years after expiration or supersession.  
instructions issued by the company to  
employees which pertain to changes in  
accounting, engineering, operating,  
maintenance, and construction policies.  
(b) Bulletins or memoranda of general  
instructions issued by the company to  
employees which pertain to accounting,  
engineering, operating, maintenance, and  
construction methods and procedures.  
Destroy at option after expiration or  
supersession.  
(c) Notices to employees on matters of  
discipline, department, and other similar  
subjects.  
Destroy at option.  
History: 1979 AC; 1980 AACS.  
Page 30  
R 460.2562 Organization diagrams and charts; retention period.  
Rule 62. Organization diagrams and charts may be destroyed at option.  
Purchase and store records.  
History: 1979 AC; 1980 AACS.  
R 460.2563 Purchase records; retention periods.  
Rule 63. The following purchase records shall be retained for the periods listed:  
(a) Advices or requisitions from  
storekeepers and others for the purchase of  
materials, supplies, or services.  
Destroy at option.  
(b) Bids received from vendors in  
connection with the purchase of materials and  
supplies.  
3 years.  
(c) Purchasing department copies of  
purchase orders and specifications of materials  
ordered.  
3 years.  
(d) Contracts for the purchase of materials  
and supplies:  
(i) Contracts for materials used directly in  
construction.  
6 years. (See rule 22(b)(i)).  
(ii) Contracts for other materials.  
6 years. (See rule 22(b)(ii)).  
Destroy at option.  
(e) Purchasing department copies of  
invoices for materials and supplies. (See rule  
24(l)(b) for original invoices).  
(f) Registers or similar records of  
invoices.  
3 years.  
(g) Price records or indexes of purchases.  
Destroy at option.  
Destroy at option.  
(h) Advices from vendors that  
acknowledge receipt of orders for materials  
and supplies, notices of shipment, packing  
slips, and copies of bills of lading.  
(i) Receipts or delivery tickets issued for  
materials and supplies received in installments  
and subsequently surrendered with, and in  
support of, invoices or bills that cover  
Destroy at option.  
Page 31  
complete purchases.  
(j) Demurrage or car records that show  
periods that freight cars are held on company  
sidings.  
(k) Copies of notices to vendors for  
materials and supplies returned for credit and  
repair.  
Destroy at option.  
Destroy at option.  
(l) Lists or records of invoices transmitted  
to or from storekeepers.  
(m) Records and reports used for checking  
and tracing materials and supplies covered by  
invoices provided for in subdivision (e) of this  
rule.  
Destroy at option.  
Destroy at option.  
History: 1979 AC; 1980 AACS.  
R 460.2564 Material ledgers; retention periods.  
Rule 64. The following material ledger records shall be retained for the periods listed:  
(a) Ledger sheets and card records of  
materials and supplies received, issued, and on  
hand.  
See rule 22 (b).  
(b) Statements of materials and supplies on  
hand, per ledger.  
Destroy at option after completion of  
annual audit by independent accountants.  
History: 1979 AC; 1980 AACS.  
R 460.2565 Records of materials and supplies received and issued; retention periods.  
Rule 65. The following records of materials and supplies received and issued shall be  
retained for the periods listed:  
(a) Records and reports that pertain to the  
receipt of materials and supplies.  
Destroy at option after completion of  
annual audit by independent accountants.  
(b) Records of inspecting and testing  
materials and supplies.  
Destroy at option.  
See rule 22(b).  
(c) Records that show the detailed  
distribution of materials and supplies issued  
Page 32  
during accounting periods.  
(d) Material disbursement tickets that  
show quantities, unit prices, and accounts to be  
charged for materials and supplies issued for  
stores for use.  
See rule 22(b).  
(e) Materials returned credit slips which  
show details of materials returned to stock.  
See rule 22(b).  
(f) Requisitions and receipts for materials  
and supplies issued, with the details of the  
issues set forth in the material disbursement  
tickets.  
Destroy at option.  
(g) Records and reports of materials and  
supplies transferred from one department,  
storeroom, or region to another.  
Destroy at option.  
Destroy at option.  
(h) Records and reports of materials  
recovered and returned to stock if transcribed  
to records covered by subdivision (c) of this  
rule.  
(i) Records and reports of materials and  
supplies to individuals or gangs of employees  
to be accounted for when used or returned to  
stock.  
Destroy at option after being accounted for.  
Destroy at option.  
(j) Minor records and reports that pertain  
to materials and supplies which do not involve  
costs or final disposition, such as reports of  
unfilled requisitions, authorizations for  
additions to stock, and similar records; also,  
storeroom copies of purchase orders and  
price records, other copies being retained in  
files of the purchasing department.  
History: 1979 AC; 1980 AACS.  
R 460.2566 Records of sales of scrap and materials and supplies; retention periods.  
Rule 66. The following records of sales of scrap and materials and supplies shall be retained  
for the periods listed:  
(a) Authorizations for the sale of scrap and  
3 years.  
Page 33  
materials and supplies.  
(b) Contracts for the sale of scrap and  
materials and supplies.  
3 years.  
(c) Memoranda pertaining to the sale of  
scrap and materials and supplies.  
Destroy at option.  
History: 1979 AC; 1980 AACS.  
R 460.2567 Inventories of materials and supplies; retention periods.  
Rule 67. The following inventory records shall be retained for the periods listed:  
(a) General inventories of materials and  
supplies on hand with records of adjustments  
of accounts required to bring store records into  
agreement with physical inventories.  
Destroy at option after completion of  
annual audit by independent accountants.  
(b) Stock cards, inventory cards, and other  
detailed records that pertain to the taking of  
inventories if abstracted into records covered  
by subdivision (a) of this rule.  
Destroy at option.  
Destroy at option.  
(c) Minor inventories of materials and  
supplies on hand if not reflected in adjustments  
of accounts.  
History: 1979 AC; 1980 AACS.  
R 460.2568 Electricity production records; retention periods.  
Rule 68. The following electricity production records shall be retained for the periods listed:  
(a) Boiler room, condenser room, turbine  
room, and pump room logs, including  
supporting data.  
3 years.  
(b) Boiler room and turbine room reports of  
equipment in service and performance.  
3 years.  
(c) Boiler-tube failure report.  
3 years.  
3 years.  
(d) Generation and output logs with supporting  
data.  
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(e) Station and system generation reports.  
25 years, except that those relating to  
licensed projects, or additions or betterments to  
those projects, for which the commission has  
not determined the actual legitimate original  
cost, shall be retained 25 years and until this  
cost has been determined.  
(f) Generating high-tension and low-tension  
load records.  
3 years.  
(g) Oil and waste reports.  
3 years.  
3 years.  
(h) Load curves, temperature logs, and coal  
and water logs.  
(i) Gage reading reports.  
2 years, except that river-flow data  
collected in connection with hydro-operation  
shall be retained for the life of the corporation.  
(j) Recording instrument charts.  
1 year, except that where the basic chart  
information is transferred to another record, the  
charts shall be retained for only 6 months if the  
record that contains the basic data is retained  
for 1 year.  
(k) Load dispatcher’s and station permits.  
1 year, except that where the basic chart  
information is transferred to another record, the  
charts shall be retained for only 6 months if the  
record that contains the basic data is retained  
for 1 year.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2568a Manufactured Gas Plant Site records; retention periods.  
Rule 68a. Manufactured gas plant site records shall be retained for a minimum of 10 years  
past an Environmental Protection Agency (EPA) or Michigan Department of Environment, Great  
Lakes, and Energy (EGLE) approval of the completed remediation or 10 years after the final  
remediation amounts have been approved by the commission, whichever is longer. The  
company shall offer to submit technical documents supporting the remedial activities to the  
commission before their destruction.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2568b Rescinded.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
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R 460.2569 Electricity transmission and distribution records; retention periods.  
Rule 69. The following electricity transmission and distribution records shall be retained for  
the periods listed:  
(a) Substation and transmission line logs.  
3 years.  
3 years.  
(b) System operator’s daily logs and  
reports of operation.  
(c) Storage battery and other equipment  
logs and records.  
3 years.  
(d) Interruption logs and reports.  
6 years.  
3 years.  
(e) Records of substation general  
inspections and operation tests.  
(f) Apparatus failure reports.  
3 years.  
3 years.  
(g) Line-trouble reports and records.  
(h) Lightning and storm data.  
(i) Insulator test records.  
3 years.  
3 years.  
(j) Reports on inspections and repairs of  
all street openings.  
6 years.  
(k) Records of meter tests.  
Until superseding test, but not less than 2  
years or as may be necessary to comply with  
service rules regarding refunds on fast meters.  
(1) Meter shop reports (monthly reports  
summarizing tests and repairs).  
3 years.  
(m) Meter history records.  
For the life of the meter or as may be  
necessary to comply with service rules  
regarding refunds on fast meters.  
(n) Transformer history records.  
For the life of the transformer.  
Destroy at option.  
(o) Records of transformer inspections  
and oil tests.  
(p) Pole, tower, structure, equipment, and  
other history records. Note: Life or mortality  
study data for depreciation purposes shall be  
For the life of the equipment.  
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retained for the life of the corporation.  
History: 1979 AC; 1980 AACS.  
R 460.2569a Gas transmission and distribution records; retention periods.  
Rule 69a. The following gas transmission and distribution records shall be retained for the  
periods listed:  
(a) Transmission line logs.  
If records are not disputed or adjusted,  
destroy after 1 year.  
(b) Transmission and distribution department  
load dispatching operating logs.  
If records are not disputed or adjusted,  
destroy after 1 year.  
(c) Service interruption logs and reports.  
6 years.  
3 years.  
(d) Records of general inspections and  
operating tests.  
(e) Reports on inspections and repairs of all  
street openings.  
6 years.  
6 years.  
(f) Apparatus failure reports.  
(g) Records of meter tests.  
Until superseding test, but not less than 2  
years or as may be necessary to comply with  
service rules regarding refunds on fast meters.  
(h) Meter history records.  
For the life of the meter.  
3 years.  
(i) Meter shop reports that are monthly reports  
summarizing tests and repairs.  
(j) Gas measuring records.  
1 year, unless measurement data have been  
disputed or adjusted.  
(k) Transmission line operating reports.  
(l) Compressor operation and reports.  
(m) Gas pressure department reports.  
1 year, unless measurement data have been  
disputed or adjusted.  
1 year, unless measurement data have been  
disputed or adjusted.  
1 year, unless measurement data have been  
disputed or adjusted.  
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(n) Recording instrument charts, such as  
pressure (static and differential), temperature,  
specific gravity, and heating value.  
1 year, unless measurement data have been  
disputed or adjusted; except that where charts  
are exchanged with the customer and the basic  
information is transferred to another record, the  
charts shall be retained for only 6 months if the  
record that contains the basic chart data is  
retained for 1 year.  
History: 1979 AC; 1980 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2569b Underground storage of natural gas.  
Rule 69b. The following underground storage of natural gas records shall be retained for the  
time periods listed:  
(a) Well records, reports, and logs that include  
data relating to pressures, injected volumes,  
withdrawn volumes, core analysis, daily  
volumes of gas injected into and withdrawn  
from reservoir, cushion, and working gas  
volumes for each reservoir.  
1 year after reservoir, field, or relevant  
storage area is abandoned.  
(b) Records containing information relating to  
reservoir gas leakage, showing the total gas  
leakage, and recycled gas.  
1 year after reservoir, field, or relevant  
storage area is abandoned.  
(c) Records on back pressure tests field data.  
1 year or until superseded.  
1 year or until superseded.  
(d) Records on back pressure test results, gas  
analysis.  
History: 1979 AC; 1980 AACS; 1998-2000 AACS; 2021 MR 22, Eff. Nov 18, 2021.  
R 460.2570 Customer service records; retention periods.  
Rule 70. The following customer service records shall be retained for the periods listed:  
(a) Reports of inspections of customer  
premises.  
2 years.  
(b) Records and reports of customer  
service complaints.  
2 years.  
(c) Surveys of customer premises to  
determine the type of service and equipment to  
be installed.  
Destroy at option.  
Destroy at option.  
(d) Records of installed customer  
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