HSBC Bank USA, National Association, an American subsidiary of UK-based HSBC, is a bank with its operational head office in New York City and its nominal head office in McLean, Virginia (as designated on its charter). HSBC Bank USA, N.A. is a national bank chartered under the National Bank Act, and thus is regulated by the Office of the Comptroller of the Currency (OCC), a part of the U.S. Department of the Treasury. The company has 159 branch locations.