24 C.F.R. § 203.558 : Housing and Urban Development — REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT — OFFICE OF ASSISTANT SECRETARY FOR HOUSING - FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT — MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES — SINGLE FAMILY MORTGAGE INSURANCE — SERVICING RESPONSIBILITIES —PAYMENTS, CHARGES AND ACCOUNTS — Handling prepayments

(a) Handling prepayments for FHA-insured mortgages closed on or after January 21, 2015. With respect to FHA-insured mortgages closed on or after January 21, 2015, notwithstanding the terms of the mortgage, the mortgagee shall accept a prepayment at any time and in any amount. The mortgagee shall not require 30 days' advance notice of prepayment, even if the mortgage instrument purports to require such notice. Monthly interest on the debt must be calculated on the actual unpaid principal balance of the loan as of the date the prepayment is received, and not as of the next installment due date.
(b) Handling prepayments for FHA-insured mortgages closed before January 21, 2015.
(1) With respect to FHA mortgages insured before August 2, 1985, if a prepayment is offered on other than an installment due date, the mortgagee may refuse to accept the prepayment until the first day of the month following expiration of the 30-day notice period as provided in the mortgage, or may require payment of interest to that date, but only if the mortgagee so advises the mortgagor, in a form approved by the Commissioner, in response to the mortgagor's inquiry, request for payoff figures, or tender of prepayment. If the installment due date (the first day of the month) falls on a nonbusiness day, the mortgagor's notice of intention to prepay or the prepayment shall be timely if received on the next business day.
(2) With respect to FHA mortgages insured on or after August 2, 1985, but closed before January 21, 2015, the mortgagee shall not require 30 days' advance notice of prepayment, even if the mortgage instrument purports to require such notice. If the prepayment is offered on other than an installment due date, the mortgagee may refuse to accept the prepayment until the next installment due date (the first day of the month), or may require payment of interest to that date, but only if the mortgagee so advises the mortgagor, in a form approved by the Commissioner, in response to the mortgagor's inquiry, request for payoff figures, or tender of prepayment.
(3) If the mortgagee fails to meet the full disclosure requirements of paragraphs (b)(1) and (b)(2) of this section, the mortgagee may be subject to forfeiture of that portion of the interest collected for the period beyond the date that prepayment in full was received and to such other actions as are provided in part 25 of this title.
(c) Mortgagee annual notice to mortgagors. Each mortgagee, with respect to a mortgage under this part, shall provide to each of its mortgagors not less frequently than annually a written notice, in a form approved by the Commissioner, containing a statement of the amount outstanding for prepayment of the principal amount of the mortgage. With respect to FHA-insured mortgages closed before January 21, 2015, the notice shall describe any requirements the mortgagor must fulfill to prevent the accrual of any interest on the principal amount after the date of any prepayment. This paragraph shall apply to any outstanding mortgage insured on or after August 22, 1991.

24 C.F.R. §203.558

79 FR 50837, 8/26/2014