It completed £24.2bn of gross mortgage lending in 2010, slightly down on £26.4bn in 2009.
In the first six months of 2010 it had gross lending of £12.3bn, slightly up on the last six months when it did £11.9bn in gross mortgage lending.
Overall Santander UK made a profit after tax of £1.7bn – up 11% on 2009.
Net mortgage lending totalled £5.5bn in 2010, also down on 2009’s £7.6bn.
The stock of properties in possession increased slightly to 873 cases from 820 in 2009, but still represents only 0.05% of the book.
The mortgage non-performing loan ratio decreased for the third consecutive quarter to 1.29% from 1.37% a year ago.
The level of arrears cases remained lower than expected, as did the average losses on repossessed properties following positive house price inflation in the first half of 2010.
It says new lending continues to focus on affordability for low risk customers. The LTV of new lending and mortgage stock was 63% and 51% respectively, broadly unchanged since last year.
Ana Botín, chief executive officer of Santander UK, says: “Santander UK delivered a strong performance in 2010, with a good flow of new business and a healthy uplift in profit despite a challenging trading environment.
“The move to a single brand, offering a range of best-buy products, was supported by prudent lending and controlled costs.
“This allowed us to continue our strong support for the UK economy, where we wrote almost one in five mortgages and increased lending to small and medium-sized enterprises by 26%.
“We enter 2011 with confidence. We are working towards completing the acquisition of 318 RBS branches, a key step in fulfilling our ambition to be a full-service commercial bank as we complement our strong retail offering with an increased presence for SMEs.
“This is an important part of Santander UK’s strategy and a vital sector for the growth of the economy. Our aim is to increase our lending to UK businesses and create new jobs as we open more business centres to serve them.”