The deal is effective from 1 May, and around five million TSB customers will join Santander UK, bringing approximately £71.5bn in gross customer assets, comprising £35.2bn in deposits and £36.3bn in lending.
This will turn the two banking brands into the third-largest bank for customer accounts and fourth-largest for mortgage lending.
Changes have also been made to the TSB board.
David Oldfield will replace Nick Prettejohn as chair, while Nicola Bannister, chief executive of TSB, Alison Straszweksi, chief financial officer of TSB, and Mahesh Aditya, chief executive of Santander UK, will sit on the TSB board.
Customers will see no immediate change; TSB and Santander UK will remain separate entities until approval is granted to integrate the two banks. TSB is now a wholly owned subsidiary of Santander UK.
Aldermore Insights with Jon Cooper: Edition 9 – Why lending strategy is becoming more central in buy to let
Sponsored by Aldermore
The transaction is expected to take place in the first half of 2027.
Bannister said: “Today marks a significant new chapter for TSB as we become part of Santander. I look forward to leading TSB as we combine the very best of these two great businesses to offer even better banking for our customers.”
Aditya added: “This is excellent news for UK banking with the acquisition representing the single largest investment in the sector for over 15 years. Bringing TSB into the Santander group strengthens competitiveness in the market and is an important step in creating the best bank for customers.
“As we enter the next phase, we remain focussed on a seamless transition, and we look forward to welcoming TSB customers as we become one of the most substantial and competitive banks in the UK – a bank positioned for sustainable growth, long-term value, and genuine differentiation.”
In its Q1 results published earlier this week, Santander said the merger would accelerate its transformation and enhance competition in the UK.
