Bill Payment Grace Period Act of 2003 - Amends the Fair Debt Collection Practices Act to prohibit creditors from taking action adverse to the interests of a consumer with respect to certain payments that are due in, or shortly after, the period of a disruption of the mail resulting from a national emergency. Authorizes the Secretary of the Treasury to designate (and extend up to seven additional days) a grace period to make debt payments by mail in such circumstances.