The Spanish bank Santander will axe their individual brands - which date back as far as 1851 - by the end of 2010 and replace them with its own global moniker.
Abbey and the B&B's savings business, snapped up by Santander in 2004 and 2008 respectively, will be the first to go, between January and March next year. A&L will follow later in 2010, according to Santander.
But it will begin introducing the Santander brand this year, by changing over Abbey credit cards under the group name, as well as the commercial and corporate banking arms of Abbey and A&L, which include 20 regional banking centres.
Santander has not drawn up plans as-of-yet to change the level of savings compensation on offer with each bank. Abbey and B&B have the same compensation coverage at present, which means a customer who has accounts with both banks would receive a maximum of £50,000 protection across the two accounts should the parent bank fail. A&L has separate coverage of £50,000.
However, a union of the three under the same compensation umbrella seems likely. It means that savers who currently hold accounts with both A&L and one of Abbey or B&B would need to move one pot to a new savings provider to benefit from the current levels of protection.
Antonio Horta-Osorio, chief executive of Santander's UK business, said customers would benefit from access to all of the group's 1,300-branch network after the rebrand is complete.
Santander is spending £12m on the rebrand, although it is aiming to save £180m from integrating the three businesses.
Around 1,900 jobs have already gone as part of its efforts to combine the acquired banks. Mr Horta-Osorio said customer feedback had shown support for the Santander brand in the UK.
'Customers trust us as a global brand and they feel very safe about their savings,' he said. 'It's important for customers who travel around the UK to have 1,300 branches to transact with - and they will have the same product and the same people facing them in the branches,' he said.
Santander has expanded aggressively in the UK over the past five years, using the banking crisis as an opportunity to buy up struggling rivals.
The group is now the UK's second biggest mortgage lender and third largest savings bank following last year's dramatic move to snap up the savings and branch operation of collapsed B&B in October, just a month after its rescue takeover of A&L.
The Government nationalised B&B's £50bn loan book, which remains in State ownership and is unaffected by the Santander rebrand.
Santander has emerged relatively unscathed from the financial turmoil, picking up swathes of savers searching for safety.
It said earlier this year that Abbey's annual pre-tax profits lifted by more than a fifth to £991m, thanks largely to the boom in savings business.
'Our prudent approach and focus on branch-based banking enabled us to acquire the A&L and B&B savings business in 2008, despite unprecedented market turmoil,' said Mr Horta-Osorio.
'Since then, we've applied the same principles to both, improving the products and services we offer as well as the business performance of each bank.'
Credit cards will be offered to new customers under the Santander brand from next month. But the group said specialist brands will retain their existing names, including internet bank Cahoot, Cater Allen, James Hy, and Abbey for Intermediaries, as well as the international businesses of all three acquired banks.
Santander has 25m customers in the UK and employs 23,000 staff. It was founded in 1857 and has since grown to become a global business with operations in 40 countries and a 170,000-strong workforce.
