Branch operations of three UK banks owned by the Spanish firm are to be merged next year.
Britain's high street banks are to look very different from next year, with Alliance & Leicester, Abbey and Bradford & Bingley all rebranding.
Branches are to be renamed Santander, as the Spanish financial services giant owns all three firms. This will allow customers of the UK banks to use 1,000 separate branches nationwide at the beginning of next year - rising to 1,300 at the year's end.
Santander has enjoyed a stronger balance sheet than rival banks in the credit crunch, allowing it to expand its position in the UK marketplace. Separate takeover deals for Alliance & Leicester and the savings business of Bradford & Bingley were agreed in mid-2008 for this reason.
Abbey had already been taken over by the Spanish group in 2004.
Antonio Horta-Osorio, chief executive of Santander's UK Businesses, said: "Bringing together the three brands means it will be even easier for customers to manage their finances as they will have access to over 1,300 branches once the change is complete. With this in mind the time is right to make the move to a single UK identity as Santander, a powerful new force in the UK banking."
Santander also claimed that it had been "prudent" in its financial practices prior to the credit crunch, allowing it to be in a stronger position to make acquisitions in the financial crisis.
A total of 25 million customers are forecast to be affected by the change.
