NatWest dates back to when National Provincial Bank, Westminster Bank and District Bank came together to form National Westminster Bank – symbolised. Online Banking. The Internet browser you are using is not supported by Online Banking. Use the link below to see a complete list of the browsers we support. National Westminster Bank Plc (date), established in London, is a constituent of The Royal Bank of Scotland Group. Life Insurance nationalwestminster bank provided by AIG. A User Paradigm Electronic Working Papers Series, no. Existing customers My Rewards Change your NatWest bank account Manage your bank account Manage gryaltomaty Direct Debits Accessible debit card. InInternational Westminster Bank was merged into National Reel king online Bank by Act of Parliament. For a more financially secure future take care of your tomorrow today.