(1) The department will provide you a service credit purchase estimate upon request. If, after receiving the estimate, you wish to purchase some or all of the available credit you must request a bill. Your request must identify the amount of service credit you wish to purchase.

(2) Your bill will be based on a specific date of payment. The cost to purchase the service credit could change if you attempt to pay after the specific payment date listed on the bill. If you do not make payment by the bill's due date but still wish to purchase service credit, you must request a new bill from the department.