12 C.F.R. § 226.10 Prompt crediting of payments.
Title 12 - Banks and Banking
(a) General rule. A creditor shall credit a payment to the consumer's account as of the date of receipt, except when a delay in crediting does not result in a finance or other charge or except as provided in paragraph (b) of this section. (b) Specific requirements for payments. If a creditor specifies, on or with the periodic statement, requirements for the consumer to follow in making payments, but accepts a payment that does not conform to the requirements, the creditor shall credit the payment within 5 days of receipt. (c) Adjustment of account. If a creditor fails to credit a payment, as required by paragraphs (a) and (b) of this section, in time to avoid the imposition of finance or other charges, the creditor shall adjust the consumer's account so that the charges imposed are credited to the consumer's account during the next billing cycle.
Title 12: Banks and Banking
PART 226—TRUTH IN LENDING (REGULATION Z)
Subpart B—Open-End Credit
§ 226.10 Prompt crediting of payments.