Figures published today demonstrate the growing strength of the financial mutual sector in the UK. Building societies and mutual-owned banks remain the driving force in the mortgage market whilst continuing to offer competitive savings rates.

In the six months to March 2025 two shareholder owned UK banks were acquired by building societies, becoming mutual-owned banks.[1]  These mutual-owned banks and building societies together hold assets of £648.3bn. They account for 29% of total UK mortgage balances and a 23% share of UK savings balances.

In the six months to March 2025, building societies and mutual-owned banks:

• Grew their mortgage balances by £14.8 billion, accounting for 52% of the growth in the mortgage market
• Attracted cash savings balances of £17.4 billion, a third of all cash saved in the period

Building societies and mutual banks support homeowners

Despite the impact of 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.

Today’s figures demonstrate that building societies and mutual-owned banks are the backbone of the mortgage market, providing over half (52%) of the growth during the period. This continues the trend of the mutual sector being the consistent driving force in the market.

Building societies and mutual banks support savers

In the six months to March 2025, building societies and mutual-owned banks attracted 33% of all UK savings, growing their balances by £17.4 billion in the period.

Building societies and mutual-owned banks also hold 47% of all Cash ISA balances, totalling £191.3 billion.  

Building societies continue to offer competitive savings. In 2024 building society savers (does not include mutual-owned banks) received £2.3 billion more in interest on their total savings than if they had been paid the average rates offered by large banks.[2]

Building societies support first-time buyers

With strong house price growth in recent years and interest rates still relatively high, the BSA Property Tracker Report shows that affordability is a significant barrier for many would-be homeowners. 

Building societies continue to provide innovative solutions to support new homebuyers, enabling them to provide 61,400 first-time buyer mortgages in the six months to March 2025 (does not include mutual-owned banks).[²]

Building societies support high streets and communities

The building society sector is committed to supporting local communities. One way they do this is by retaining high street branches. Building societies’ current share of high street branches is 30%, more than double the proportion they had in 2013 (14%) (does not include mutual-owned banks).[²]

Ends

Notes

• The data is based on returns made to the BSA by building societies, including the two mutual-owned banks. Comparisons made with the rest of the market are calculated using the Bank of England’s total market data. Data tables can be found on the BSA website here.

• Branch data is compiled by the BSA from its members, ILMA24, bank websites, and other data sources, as at end 2024.

• The Building Societies Association (BSA) represents all 42 UK building societies, including both mutual-owned banks, as well as 7 of the largest credit unions. Building societies and mutual-owned banks have total assets of almost £648.3 billion and together with their subsidiaries, hold residential mortgages of over £485.6 billion, 29% of the total outstanding in the UK. They also hold £485.7 billion of retail deposits, accounting for 23% of all such deposits in the UK. Building societies and mutual-owned banks account for 47% of all cash ISA balances.

• With all of their headquarters outside London, building societies employ around 52,300 full and part-time staff.  In addition to digital services, they operate through approximately 1,300 branches, holding a 30% share of branches across the UK.

Press contacts:

Pressoffice@bsa.org.uk

Katie Wise, katie.wise@bsa.org.uk
Debbie Enever, Debbie.enever@bsa.org.uk

Appendix

Key trading figures for the past six months

Building society and mutual-owned banks mortgage lending - Oct 2024 to Mar 2025[3]

• Gross mortgage lending of £46.5 billion, a 32% market share of all lending 
• 208,139 mortgage approvals, a 33% market share of all approvals
• Net lending was higher than the total lending at all other lenders, at £14.7 billion, a 52% share of total net lending
• At the end of March 2025, building societies and mutual-owned banks had mortgage balances of £485.6 billion, a 29% share of total UK mortgage balances.

Building society and mutual-owned banks savings deposits - Oct 24 to Mar 2025^[3]

• Savings balances increased by £17.4 billion, a 33% share of all UK savings
• At the end of March 2025, building societies and mutual-owned banks had savings balances of £485.7 billion, a 23% share of total UK savings balances.
• At the end of March 2025, building societies and mutual-owned banks had Cash ISA balances of £191.3 billion, a 47% share of total UK Cash ISA savings balances.