The building society and mutual sector’s assets came to £643.8bn, equal to 29% of UK mortgage balances and a 23% share of UK savings balances.
The latest figures from the Building Societies Association (BSA) – which includes all 42 UK building societies, including both mutual-owned banks and seven of the largest credit unions – show that in the six months from October to the end of March, mortgage balances came to £485.6bn, 29% of total UK mortgage balances.
This is a growth of £14.8bn, accounting for around 52% of growth in the mortgage market, the BSA said.
The report added that gross mortgage lending is estimated at around £46.5bn, around 32% of all lending.
Building societies have also accounted for around 208,139 mortgage approvals during the same period, a third of market share.
The report added that building societies, not including mutual-owned banks, supported 61,400 first-time buyers during the period.
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The report said part of the growth was due to acquisitions, with Virgin Money being acquired by Nationwide Building Society in 2024 and The Co-operative Bank being bought by Coventry Building Society in January 2025.
The BSA added that despite the stamp duty deadline at the end of March, the housing market is “being supported by strong growth in wages and a relatively resilient labour market, however affordability pressures remain an issue, especially for first-time buyers”.
It continued on to say that building societies and mutual-owned banks were the “backbone of the mortgage market” and a “consistent driving force in the market”.
