Santander UK reported a sharp increase in its mortgage portfolio following the completion of its acquisition of TSB.
Mortgage deposits rose to £204.7 billion according to the lender’s half-year results to the end of June, up from £169 billion at the end of 2025, an increase of £35.7 billion.
The deal makes Santander the fourth largest mortgage lender in Britain.
Gross mortgage lending also rose to £14.7 billion in the first half of 2026, up from £10.6 billion a year earlier.
Chief executive Mahesh Aditya said the integration of TSB was a major piece of work for the lender after the acquisition was completed on April 30.
He added that the expanded bank now serves an additional four million customers and has become the third largest provider of personal current accounts in Britain.
Santander said it expects net lending growth to continue into 2026.
The banks’ net interest margin is expected to remain stable, while the lender expects cost efficiency to further improve as TSB is integrated and its operations further simplified and automated.
Asset quality across the entire mortgage portfolio remained strong, according to the bank.
Mortgage arrears remained low over the period, while the Phase 3 loan ratio fell to 0.85%, partly due to a previously completed sale of higher risk mortgage assets.
Customer deposits also rose to £227.2 billion, largely due to the TSB acquisition and continued demand for fixed-term savings products, which provided continued support for mortgage lending.
Santander’s pre-tax profit fell 31% year-on-year to £528 million, mainly due to payouts for historic car finance commission claims and restructuring costs.
The bank said underlying lending activity was resilient.