Challenger banks and specialist lenders grew their gross lending by 56 per cent last year, according to the Council of Mortgage Lenders.
The increase gave the sector a 2.9 per cent increase in market share.
Banks increased their gross lending by 4 per cent and building societies by 9 per cent.
GROWTH IN GROSS LENDING 2014-15
Total gross lending in 2015 was £220bn, up 8 per cent on the year before. A CML spokesman noted that the market was still “highly competitive”.
The CML has also ranked lenders in the UK in terms of size by gross lending.
The top four 2015 positions are unchanged on 2014: Lloyds, Nationwide, Santander and Royal Bank of Scotland.
RBS has switched positions with Barclays to become the fifth largest lender.
The top ten are:
Challenger banks and specialist lenders moved the most up the rankings.
Of the 16 challenger/specialist lenders on the list, 11 increased their gross lending enough to move up.
The biggest increase was Metro Bank, which moved from 24th to 16th spot by increasing its gross lending from £500m to £1.5bn in a year.
CML members wrote 97 per cent of all UK gross mortgage lending and outstanding mortgages in 2015.