The largest 10 professional trustee firms now oversee almost half of UK DB pension assets with assets — up from just under a third in 2020.
In total these firms oversee 2,400 pension schemes with assets over more than £1 trillion.
This latest survey shows the increasingly important role professional trustees play in the UK DB market, with the total share their oversee rising from 31 per cent to 45 per cent in the past five years.
This comes as rising governance expectations and regulatory scrutiny drive schemes to seek more specialist support.
These figures were contained in Isio’s latest Professional Independent Trustee Survey.
Despite the overall number of DB schemes declining, the share of the market overseen by the largest professional trustee firms has continued to increase. Isio projects that these firms could be responsible for managing around two-thirds (c.66 per cent) of DB schemes within the next five years, underlining the continued shift towards scale in trusteeship.
This trend reflects a broader shift across the pensions landscape, as trustee boards respond to increasing expectations around governance, oversight and decision-making.
Regulatory developments, including the Government’s focus on trustee capability and The Pensions Regulator’s move towards more proactive supervision, are contributing to a higher bar for governance across schemes.
While the number of appointments has remained broadly stable, underlying demand for professional trustees continues to grow.
In 2025, companies reported 174 new appointments, broadly offset by schemes reaching endgame and some mandates moving between providers, resulting in a stable overall number of mandates.
However, professional trustee companies reported significantly increased workloads across existing schemes, driven by governance requirements, data remediation, and preparation for risk transfer. This has supported continued growth, with average revenues rising by 12 per cent over the year, despite little change in total appointments.
Isio says these findings highlight that demand is increasingly being driven by complexity and project activity, rather than expansion in the number of schemes.
Corporate sole trusteeship remains a key feature of this evolution, with sole trustee roles now accounting for over half (c.55 per cent) of all appointments across the largest firms.
Around 48 appointments transitioned to a sole trustee model in 2025, with corporate sole trustees now overseeing approximately £80bn in assets. This trend is expected to continue, with projections suggesting sole trusteeship could account for around 65 per cent of appointments over the next five years.
As the market evolves, there are also signs of increasing maturity and competition between firms. While the majority of new appointments still involve schemes appointing a professional trustee for the first time (c.60–90 per cent of new mandates), a growing proportion now reflects replacement activity (10–40 per cent), as schemes review governance arrangements and re-tender roles.
This shift signals a more competitive and developed market, where differentiation in governance approach, service delivery, and expertise is becoming increasingly important.
The survey also highlights continued growth among mid-tier firms, which collectively manage around 250 schemes and £74bn in assets. These firms have seen appointments increase by around 14 per cent over the past year, demonstrating that while the largest providers are increasing their share of the market, competition remains strong.
Isio director Harvi Rana says: “Professional trustees are playing an increasingly important role in supporting pension schemes as governance expectations continue to evolve. As schemes progress towards endgame and navigate a more complex regulatory environment, there is a clear need for robust oversight and specialist expertise.
“What we are seeing is a shift in how demand is developing. Growth is no longer being driven simply by an increase in the number of schemes, but by the complexity of the work required to manage them effectively. This is reinforcing the role of professional trustees in helping schemes make well-informed decisions at critical stages in their journey.
“As a result, the largest firms are overseeing a growing share of the market, reflecting the value placed on experience, scale and governance capability in today’s pensions landscape.”