However its net lending growth slowed to £1.8bn from £1.9bn in 2016.
Leeds Building Society increased its pre-tax profit by 3.7% to £120.9m in 2017, up from £116.6m in 2016.
However its net lending growth slowed to £1.8bn from £1.9bn in 2016.
The society's mortgage balances reached £15.2bn in 2017, a 13% increase on the £13.4bn recorded in 2016.
Peter Hill, chief executive of Leeds Building Society, reckoned the society made rapid improvements in its customer retention in 2017.
He said: “Our successful mortgage strategy and improved underwriting processes have supported sustained lending growth in recent years which, combined with a further reduction in loss charges, helped us achieve a record profit before tax of £120.9m."
But he added: “Uncertainty around the UK’s exit from the EU remains. We also expect 2017’s tough competition, particularly in the mortgage market, to continue and this is likely to put downward pressure on our net interest margin during this year and into 2019."
“However our robust 2017 performance means we’re well-placed to withstand economic uncertainty, protect our members' money and keep growing sustainably.
In 2017 Leeds helped more than 50,000 people get on the housing ladder, including 13,000 first-time buyers.
