Postal Banking Act This bill grants the U.S. Postal Service (USPS) the power to provide basic financial services, including: low-cost, small-dollar loans, in specified amounts; small checking accounts and interest-bearing savings accounts in specified amounts, alone or in partnership with depository institutions and federal credit unions; transactional and remittance services; and other basic financial services in the public interest. It grants the USPS the power to: (1) set interest rates and fees for the financial instruments and products provided by the USPS that meet specified requirements, and (2) allow capitalization of an amount deemed necessary by the USPS to finance the services provided by this bill. The USPS: (1) shall not be granted a bank charter, become an insured depository institution, or engage in traditional banking activities such as lending; and (2) shall be subject to the provisions of the Uniform Commercial Code regarding bank deposits and collections.