(a) Periodic MIP which are received by the Commissioner after the payment dates prescribed by §§ 203.262 and 203.264 shall include a late charge of four percent of the amount paid.

(b) In addition to the late charge provided in paragraph (a) of this section, the mortgagee shall pay interest on any periodic MIP which are remitted to the Commissioner more than 20 days after the payment dates prescribed in § 203.264. Such interest rate shall be paid at a rate set in conformity with the Treasury Financial Manual.