(a) A mortgagee shall not commence foreclosure when the only default on the part of the mortgagor is the failure to pay a late charge or charges (§ 203.25), except as provided in § 203.556.

(b) A late charge attributable to a particular installment payment due under the mortgage shall not be deducted from that installment. However, if the mortgagee thereafter notifies the mortgagor of his obligation to pay a late charge, such a charge may be deducted from any subsequent payment or payments submitted by the mortgagor or on his behalf if this is not inconsistent with the terms of the mortgage. Partial payments shall be treated as provided in § 203.556.

(c) A payment may be returned because of failure to include a late charge only if the mortgagee notifies the mortgagor before imposition of the charge of the amount of the monthly payment, the date when the late charge will be imposed and either the amount of the late charge or the total amount due when the late charge is included.

(d) During the 60-day period beginning on the effective date of transfer of the servicing of a mortgage, a late charge shall not be imposed on the mortgagor with respect to any payment on the loan. No payment shall be treated as late for any other purpose if the payment is received by the transferor servicer, rather than the transferee servicer that should receive the payment, before the due date (including any applicable grace period allowed under the mortgage documents) applicable to such payment.