NatWest Bank Contact Number 0345 788 8444 About NatWest National Westminster Bank, commonly known as NatWest Bank, is a large retail and commercial bank in the United Kingdom. Since 2000 it has been a part of The Royal Bank of Scotland Group. NatWest along with the Scotland Group has been ranked amongst the top 10 largest banks worldwide  by their assets and resources. NatWest was established in 1968 by the merger of National Provincial Bank, which was established in 1833 …