In its half-year results update, the society reported its gross mortgage market share also shrunk, covering 2.5 per cent of the whole UK market compared to 2.9 per cent at the end of 2019.
Overall, the mutual’s total mortgage balances have remained flat at £38bn.
The society pledged to remain in the 90 per cent loan to value lending space for as long as service levels allowed and said it expected the mortgage market to remain competitive for the rest of the year, especially with the stamp duty holiday encouraging activity.
YBS said recent mortgage performance had been encouraging, adding it had established a “healthy pipeline” of new mortgage business for the second half of the year.
Its profit before tax also saw a decline as it reached £67.3m in the first half of the year, down from £76.5m during the same period last year.
As it passed the historically low bank rate saving onto its mortgage and savings customers, the society reported a fall in its net interest income from £229.6m to £211.4m. This represented a net interest margin of 0.95 per cent compared to 1.06 per cent for the equivalent period last year.
Its closing cash balance was reported as £3.05bn, up from £2.6bn in the first half of 2019.
Mike Regnier (pictured), chief executive of Yorkshire Building Society, said: “I’m pleased to report that our 2020 half-year performance illustrates that our prudent strategy over the longer term has enabled us to weather the challenging economic environment and impacts of Covid-19.
“Our balance sheet has stayed strong, our statutory and core profits remain healthy and we retain strong levels of capital and liquidity.”