FMS will transmit amounts collected for past-due, legally enforceable debts, less fees charged under this section, to the FDIC's account. The FDIC will reimburse FMS and the IRS for the cost of administering the tax refund offset program. FMS will deduct the fees from amounts collected prior to disposition and transmit a portion of the fees deducted to reimburse the IRS for its share of the cost of administering the tax refund offset program. To the extent allowed by law, the FDIC may add the offset fees to the debt.