Figures published today show that the building society sector continues to strengthen its position in the mortgage and savings markets, delivering growth that outpaces their share of balances and offering consumers an alternative to shareholder-driven banks.

In the six months to September 2025, building societies and the two mutual-owned banks¹ increased their mortgage balances by £7.5 billion, to £493 billion and grew cash savings balances by £8.8 billion, to £496 billion.

Supporting homeownership

Building societies and mutual-owned banks hold 29% of the UK’s outstanding mortgage balances yet provided 32% of the UK’s net lending in the period. More than 220,000 new mortgages were approved, representing 31% of all market approvals.

Building societies’ support for first-time buyers remains significant, as they continue to offer innovative solutions to the barriers faced by aspiring homeowners. In the six months to September 2025, they provided 59,861² mortgages to first-time homebuyers.

Supporting savers

Building societies and mutual-owned banks continue to attract a high proportion of savings. They received 27% of all UK cash savings in the six months to September 2025, considerably higher than their 23% market share of savings balances.

Building societies and mutual-owned banks hold 46% of all Cash ISA balances, totalling £205.0 billion, double their share of the total savings market. This reflects consumer appetite for providers offering straightforward products and competitive long-term value.   

Supporting communities

The member-ownership model enables building societies to focus on value for consumers rather than external shareholders. Last year members received an extra £4 billion³ in additional benefits compared to the rates and benefits offered by banks.

At a time when many banks have reduced their face-to-face services, building societies continue to maintain a strong high street presence, supporting access for consumers who value in-person services. With a number of building societies actively opening new branches and innovating how they use them, such as sharing their space with local charities and community groups, they now account for 35%² of all high street branches, up from 14% in 2012.

Building societies’ support for local communities also includes the provision of financial education and initiatives like UK Savings Week, which help individuals and families build financial confidence and resilience.

Commenting on the half year figures, Robin Fieth, Chief Executive of the Building Societies Association said:

“Consumers are increasingly looking for providers that offer long-term value, fairness and inclusive access to services in their communities.  These latest figures show that building societies continue to meet that demand, supporting people to buy their first home and helping households build their financial resilience.

“As member-owned organisations, our focus is on delivering real benefits to consumers and ensuring that value stays within local communities rather than being directed to external shareholders.
“While banks retreat from high streets and cut the local services communities rely on, building societies are doing the opposite – not only are they keeping branches open, but they are investing in them and opening new ones.

“Last week we launched the Building Society Sector Growth Plan, which called on government and regulators to drive capital reforms that would unlock the full potential of the sector. These changes will enable building societies to help even more people to buy their own home, safeguard their savings and strengthen communities across the UK. We’re not asking for special treatment, just recognition of the vital role building societies play in ensuring the UK has a diverse and competitive financial services market and the ability to realise the full potential of the sector.”

Ends

References
¹ Virgin Money was acquired by Nationwide Building Society in October 2024. The Co-operative bank was acquired by Coventry Building Society in January 2025
² Building societies only – data for mutual-owned banks currently unavailable
³ Building societies’ members only, excludes mutual-owned banks. Source: building societies annual reports 2024/25

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 ILBA24in July 2025.

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 £677 billion and together with their subsidiaries, hold residential mortgages of £493.4 billion, 29% of the total outstanding in the UK. They also hold £495.6 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 35% share of branches across the UK.