Firms are willing to diversify, but acutely aware expansion alters risk
Britain's mid-tier accountancy firms are quietly remaking themselves, moving beyond the familiar terrain of audits and tax returns into the more uncertain ground of sustainability consulting, technology advisory, and ESG frameworks. The shift is driven not by restlessness but by necessity — clients are growing more complex, and firms that cannot meet that complexity risk becoming irrelevant. Yet expansion carries its own gravity: new services bring new liabilities, and the profession is learning that growth and prudence must be built together, or not at all.
- Client demand for ESG and technology guidance is pulling mid-tier firms into territory where their traditional expertise offers little protection against new forms of professional liability.
- The deliberate avoidance of PIE audit work — rejected by 93% of eligible firms on strategic grounds — reveals a sector that is expanding selectively, not recklessly.
- Staff training, governance reform, and professional indemnity coverage are racing to keep pace with service lines that are being launched faster than the risk frameworks designed to support them.
- Private equity consolidation and generative AI are reshaping the competitive landscape beneath firms' feet even as they attempt to diversify above it.
- The sector's trajectory is toward growth, but the firms that survive the transition will be those that treat risk management as a core competency, not an afterthought.
Britain's mid-tier accountancy firms are at a crossroads. The foundational work — audits, tax, accounts preparation — still sustains them, but clients are arriving with needs that reach far beyond it. Sustainability reporting, cybersecurity, digital transformation, ESG frameworks: these are the new demands, and firms are responding. Thirty-six percent already offer ESG services; another forty-four percent plan to within three years.
What is equally revealing is what firms are choosing not to do. Despite regulatory efforts to open the market for Public Interest Entity audits, only twenty-two percent of mid-tier firms have entered that space. The reasons are deliberate: misalignment with strategy, the cost of restructuring, and the weight of regulatory compliance. These are not firms lacking ambition — they are firms making careful calculations about which risks are worth accepting.
The same logic governs the move into advisory services. Unlike traditional compliance work, where errors are bounded and often correctable, advisory missteps — a flawed sustainability assessment, a digital transformation that unravels — can carry serious reputational and legal consequences. Sixty-nine percent of firms planning ESG launches are investing heavily in staff training, acknowledging that credible advice in this space demands specialist knowledge most accountants do not yet hold.
The broader forces reshaping the sector — private equity investment, consolidation, and the arrival of generative AI — add further pressure. Fee growth is coming largely from new clients and higher rates, not new services alone, suggesting that diversification is less about immediate revenue than about long-term relevance.
The firms that navigate this moment well will be those that build risk frameworks as carefully as they build service offerings — tightening governance, evolving their insurance coverage, and deepening internal expertise. The profession is adapting. Whether it can do so safely remains the defining question.
Britain's mid-tier accountancy firms are at a crossroads. The work they have always done—audits, tax returns, accounts preparation—still pays the bills. But their clients are asking for more. They want guidance on sustainability reporting. They need help navigating cybersecurity and digital transformation. They're wrestling with environmental, social and governance frameworks that barely existed five years ago. The firms sense the opportunity. They also sense the danger.
According to research from the ICAEW's 2025 study on the evolution of mid-tier firms, the profession is actively reshaping itself. Thirty-six percent of mid-tier accountancy firms now offer environmental, social and governance services. Another forty-four percent plan to launch these offerings within three years. The demand is real. But so is the risk.
The pattern is clearest when you look at what firms are choosing NOT to do. Regulatory reform has tried to open the audit market to more competitors, particularly for Public Interest Entity audits—the high-stakes work of auditing large, regulated companies. Yet only twenty-two percent of mid-tier firms have taken on PIE audit work. Among those that haven't, the reasons are strikingly consistent. Ninety-three percent say the work doesn't fit their strategy or risk appetite. Eighty-eight percent point to the cost of hiring and restructuring. Eighty-two percent cite regulatory compliance expenses as a barrier. These aren't firms lacking ambition. They're firms making deliberate choices about which risks they'll accept and which they'll avoid.
The same calculation applies to newer advisory services. When a firm moves into ESG consulting or technology advisory, it's not simply adding a new revenue stream. It's introducing new kinds of professional liability. An error in traditional compliance work—a missed deduction, a miscalculated provision—is bounded and often fixable. An error in advisory work can be far more consequential. If a firm advises a client on sustainability metrics and that advice turns out to be wrong, or if it guides a company through a digital transformation that goes sideways, the firm's reputation and its insurance coverage are both at risk. Sixty-nine percent of firms planning to launch ESG services are investing heavily in staff training, recognizing that credible advice in this space requires specialist knowledge that most accountants don't yet possess.
The broader context matters here. Mid-tier firms are being reshaped by private equity investment, by acquisitions and consolidation, and by the arrival of generative AI in professional services. Fee growth across the sector is being driven mainly by new clients and higher charge-out rates, not by new service lines alone. This suggests that diversification is less about immediate revenue and more about survival—about staying relevant to clients whose needs are becoming more complex and interdisciplinary.
But as firms expand, their risk exposure expands with them. Professional indemnity insurance must evolve. Governance structures must tighten. Internal expertise must deepen. The firms that manage this transition well—that build robust risk frameworks alongside new service offerings—will be positioned to grow. Those that don't will face the prospect of regulatory scrutiny, reputational damage, and costly claims. The profession is adapting. The question now is whether it can adapt safely.
Notable Quotes
Firms are willing to diversify their services, but they are acutely aware that expansion into highly regulated or technically complex areas can significantly alter their risk profile— ICAEW Evolution of Mid-Tier Accountancy Firms 2025 research
The Hearth Conversation Another angle on the story
Why are firms so cautious about PIE audits when regulators have tried to open that market up?
Because the regulatory burden is real, and it's not just about compliance. A PIE audit means you're auditing a company that matters to the public—a bank, an insurance firm, a large employer. If something goes wrong, regulators come looking. You need the right people, the right systems, the right insurance. For a mid-tier firm, that's a massive investment with no guarantee of return.
So it's not that they can't do the work. It's that the risk-reward doesn't make sense.
Exactly. And that's actually a sign of maturity in the profession. Firms are being honest about their appetite for risk rather than chasing every opportunity.
What about ESG services? Those seem to be taking off.
They are, but for different reasons. Clients are demanding them, and the regulatory burden is lighter—at least for now. But the professional liability risk is different. You're interpreting emerging frameworks, advising on metrics that are still being defined. If your advice turns out to be wrong, you're exposed.
Is that why so many firms are investing in training?
Yes. Sixty-nine percent of firms launching ESG services are training their staff specifically because they know the knowledge gap is real. You can't just reassign an audit partner to ESG advisory and hope for the best.
What happens to firms that expand without building the right infrastructure?
They take on liability they can't manage. Regulatory scrutiny. Reputational damage. Claims they didn't anticipate. The firms that survive this transition are the ones that treat service expansion as a governance problem, not just a revenue opportunity.
So the real story is about risk management, not growth.
It's both. But growth without risk management is just exposure.