The rebranding in the UK is in line with Santander's policy of operating under the Santander name and brand image in all the markets in which it is present. Since the unified brand was introduced in 2005, Santander has rebranded in all its key markets, including Spain, Portugal, Germany, Brazil, Mexico, Chile and Argentina.
Emilio BotÃn, chairman of Banco Santander, said: "This is a historic day for Santander as its name is firmly established on the UK high street.
"When Santander acquired Abbey in 2004, there were some who doubted we could make it a success. Today, there can be no doubts. Over the last five years we have transformed our UK business into one of the most successful banks in the country. The decision to become Santander will put us in an even stronger position the UK."
AntÃ³nio Horta-OsÃ³rio, chief executive of Santander UK, added: "The success of our UK business has given us the confidence to move to the Santander name now and with it deliver the next phase of our transformation programme and make 1300 branches available to our 25 million customers in the UK.
"I am confident that this is a very positive move - both for our customers and our employees."