The paper begins with a brief discussion of the changes to the personal sector financial services market since deregulation in the late 1980s, dealing in particular with the impact these changes had on the banking sector in the United Kingdom. A detailed exploration of the changing customer base for Barclays Bank, follows. It begins with the segmentation of customers in terms of demographics, and moves on to an understanding of customer motivations. The paper culminates in a detailed exploration of buying behaviour, out of which an overall generic model of buyer behaviour for the personal sector of the financial services market was produced. The paper also deals with Barclays' implementation of the key findings from this research process, giving indications, where appropriate, of the effect on the Bank's current marketing strategy.