Upon notice from a mutual company of the actual amount of premium to be returned to the local agency, the amount stated shall be entered on a journal voucher for recording in the general ledger as follows:

Any debit or credit balance remaining in account 1212 shall be transferred to the applicable cost or expense account, except that during the operating period of the project proper such debits or credits as do not apply to the current fiscal operating year shall be transferred to account 2710, Prior Years Adjustments, on a pro rata basis. The proration between the current and prior fiscal operating years shall be determined by applying the balance in account 1212 over the life of the policy on the same basis as prescribed for monthly charges. The amount charged or credited to account 6010, Prior Years Adjustments, shall be cleared out of the latter account along with the other charges or credits made thereto, as described in Part 1647, Operating Period Accounting.