(a) Required charge. In the case of an insured open-end advance the mortgagee shall pay to the Commissioner an open-end insurance charge.

(b) Payment of charge for mortgages with periodic MIP. The amount of any insured open-end advance shall be added to the average outstanding principal obligation of the mortgage for the purpose of determining the amount of periodic MIP as provided in §§ 203.260 through 203.268, except that the initial additional charge shall be prorated to cover the period beginning with the first day of the month following the issuance of a certificate evidencing the insurance of the open-end advance and ending on the due date of the next MIP.

(c) Payment of charge for mortgages with one-time or up-front MIP. In the case of a mortgage with a one-time or up-front MIP pursuant to § 203.280, § 203.284, or § 203.285 of this part, the insurance charge shall be in an amount equal to 1⁄2 percent per annum of the outstanding principal obligation of the open-end advance. Sections 203.260 through 203.268 shall apply to the open-end charge on a mortgage with a one-time or up-front MIP, except that all references to amortization dates shall refer to amortization dates of the open-end advance, references to MIP shall refer to the open-end insurance charge, and references to outstanding principal obligation of the mortgage shall refer to outstanding principal obligation of the open-end advance.

(d) Method of payment - all mortgages. The payment of any open-end insurance charge under this subpart shall be made to the Commissioner by the mortgagee either in cash or debentures issued by the Mutual Mortgage Insurance Fund at par plus accrued interest.