((a)) In this section, “service” includes service provided in—
((1)) disbursing and receiving amounts.
((2)) servicing bonds.
((3)) making accounts.
((4)) maintaining bank accounts.
((b)) When the Secretary of the Treasury provides a service for an agency (except the Department of the Treasury) for which amounts have not been appropriated to the Department, the agency may advance for credit or reimburse the Department the amounts necessary to provide the service. Notwithstanding , amounts advanced or reimbursed may be credited to the appropriation of the Department that is current when the service is provided.