Mich. Comp. Laws § 129.14: Deposit or investment of additional money; cash control ledger; limitation.

Sec. 4.

(1) Notwithstanding section 2, additional money collected or received by a treasurer of a local public entity must not be deposited or invested in a financial institution that is not eligible to be a depository of surplus funds of this state under section 6 of 1855 PA 105, MCL 21.146.

(2) An officer of a local public entity responsible for depositing money belonging to the local public entity shall keep all accounts at a financial institution designated under this act upon the regular books or records of the officer so that each item of all accounts appear on the books or records and shall maintain a cash control ledger recording deposit and investment activity affecting the money, including, but not limited to, a record of the cash and investment equity of each fund of the local public entity. Money deposited with a treasurer under this act, including any surplus money, must be deposited in a financial institution designated by the local public entity under this act or be invested by the treasurer as investment officer for the local public entity in a manner that complies with 1943 PA 20, MCL 129.91 to 129.97a.