The UK’s 10 largest professional trustee firms now manage 43 per cent of all defined benefit (DB) pension schemes, up from 39 per cent last year, according to Isio.
According to Isio’s 2025 Professional Independent Trustee Survey these firms oversee more than 2,400 schemes, with combined assets exceeding £1 trillion.
The report found that the number of trustee directors across the top 10 firms rose from 320 to 350 in the past year, while average revenue increased by 15 per cent, marking the fifth consecutive year of double-digit growth. Isio predicts these firms could be managing two-thirds of DB schemes within five years.
According to Isio, a key driver of this growth is the shift to corporate sole trusteeship, where a single professional firm replaces a traditional trustee board. These now account for 48 per cent of all trustee appointments, up from 41 per cent in 2020. Sole trustee firms currently manage around £70 billion in assets, with the largest scheme valued at £3.4 billion. In 2024, 50 existing schemes moved to the sole trustee model, and Isio expects this trend to accelerate.
Additionally, women now make up 44 per cent of trustee directors at the top 10 firms, compared to just 24 per cent across the rest of the market. But ethnic diversity is still limited, with 8 per cent of directors from minority backgrounds, slightly ahead of the industry average of 5 per cent.
The survey also highlights seven mid-sized firms managing around 200 appointments and £13 billion in assets, suggesting further competition and potential growth in the coming years.
These changes come as The Pensions Regulator plans to bring in new rules to better oversee professional trustees, something most firms are on board with.
Isio director Harvi Rana says: “Professional trustee firms play an increasingly central role in the UK’s pensions market. As DB schemes mature and reach critical phases in their individual journeys and endgame planning, the involvement of a professional trustee is clearly proving instrumental to securing the best possible future for these schemes.
“As a result of the success of professional trustees, particularly within the ten largest firms in the industry, they have secured a position of integral importance in the UK pensions market, and their extensive operations are now attracting increased attention. The influence of professional trustees will continue to grow, and the Regulator’s intentions to introduce a new oversight framework reflects the increasingly key role they will play in safeguarding and securing the future of DB schemes.”
