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. |
(b) Record or register of accounts receivable and indexes thereto and summaries of distribution. | 3 years after settlement. |
(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. |
(e) Schedule of invoices to be issued. | Destroy at option. |
Mich. Admin. Code R. 460.2526