12 CFR § 614.4175 - Uninsured voluntary and involuntary accounts.
(a) Borrowers may make voluntary advance payments on their loans or, under agreement with a System institution, may make voluntary advance conditional payments intended to be applied to future maturities. The monies in the advance conditional payment accounts may be available for return to the borrower in lieu of increasing his loan. System institutions may pay interest on advance conditional payments for the time the funds are held unapplied at a rate not to exceed the rate charged on the related loan(s). System institutions shall hold any advance conditional payments received in accordance with this section in voluntary advance payment accounts.
(b) System institutions may establish involuntary payment accounts including, but not limited to, funds held for the borrower, such as loan proceeds to be disbursed for which the borrower is obligated; the unapplied insurance proceeds arising from any insured loss; and total insurance premiums and applicable taxes collected in advance in connection with any loan.