Total gross mortgage lending in July increased to £16.6 billion, up 12% from £14.8 billion in June.
The figures from the Council of Mortgage Lenders showed an increase of 29% from the total of £12.9 billion at the same time last year.
The figure is the highest monthly estimate for gross lending since October 2008 (£18.6 billion).
CML market and data analyst Caroline Purdey said: "An improvement in sentiment and activity continues to show in the UK housing and mortgage markets, with a more positive picture also starting to emerge in the economy.
"Our forward estimate of gross mortgage lending in July reinforces a growing evidence base of a strengthening in the housing and mortgage markets."
