TSB has increased its mortgage lending by 21.1% in the first half of 2016 from H1 2015.
The bank lent £23.1bn after attracting £3bn worth of applications from brokers in H1.
At the same time the lender grew its overall balance sheet, which includes former Northern Rock and Lloyds loans, by 29% to £27.9bn.
£2.7bn Northern Rock loans were transferred to TSB in December 2015.
Roland McCormack (pictured), TSB’s intermediary director, said: “The first half of the year was another period of strong growth for TSB.
“We continue to deliver an award-winning expert to expert service to our brokers, and we’ve also continued to innovate and improve our products and services.”
McCormack added that TSB’s scan and upload system has proved popular with brokers, which allows them to submit applications on their mobiles.
TSB has invited 5,000 brokers to use the service, of which 29% have registered.