Professional services are carrying more of the UK economy than almost any other part of it right now. The wider professional and business services sector accounts for close to 12% of UK output and employs around 5 million people. RSM’s analysis of the latest ONS figures found professional, scientific and technical activities drove 37% of all UK GDP growth in the second quarter of 2026, and were the fastest growing part of the services economy in June.
Source: RSM analysis of ONS figures.
So the sector is growing. Plenty of the firms inside it aren’t. And the reasons have very little to do with demand.
I spent my career as a client of professional services firms, and I’m now building one. The challenges look different in a five-partner practice and a Big Four firm, but the shape of them is remarkably consistent.
Busy is not the same as growing
The most misleading measure in a professional services firm is how busy everyone feels.
Source: SPI Research 2026 benchmark, 509 professional services organisations.
That combination tells you something important. People are working flat out, but a third of their time isn’t generating fees. It’s disappearing into internal meetings, rework, poorly scoped projects, write-offs and admin nobody has ever questioned. In a business where time is the product, that’s the growth plan leaking out of the building every week.
The billable hour is under pressure
Most firms still price on time, and that model is being squeezed. PwC’s 2025 Law Firms’ Survey points to a pronounced shift away from hourly billing towards fixed fees.
Source: PwC 2025 Law Firms’ Survey; SPI Research.
The logic is simple. If AI lets a firm do in two hours what used to take ten, and the firm bills by the hour, it has just cut its own revenue on that work by 80%. Clients know this. The firms that grow over the next few years will be the ones that price the value of the outcome rather than the time it took, and redesign how work gets delivered to protect margin. Most haven’t started.
Growth depends on too few people
In most professional services firms, growth is tied to a small number of individuals: the partners who win the work, hold the client relationships and sign off the quality. That works until those people run out of hours.
At the smaller end of the market, the constraint is often simply people.
Source: 2025 AccountingWEB survey.
The largest firms are facing the same structural question from the other direction.
When growth slows, the partnership pyramid stops working the way it was designed to.
Business development is left to chance
Most firms grow on referrals and reputation, and for years that was enough. It’s becoming much less reliable.
Source: Hinge Research 2026 High Growth Study.
The point isn’t that every firm should double its marketing budget. It’s that the firms pulling ahead treat winning work as a managed process, with owners, targets and data, rather than something partners fit in around delivery when they have time. Which, as the utilisation numbers show, they rarely do.
Confidence runs ahead of delivery
The ambition is certainly there.
Source: Management Consultancies Association; CBI, September 2026.
The distance between what a leadership team expects to deliver and what the firm is currently built to deliver.
Professional services firms aren’t short of ambition, intelligence or work ethic. They’re often short of the operating discipline they’d insist on for their own clients.
What actually moves the needle
This is where the Limitless Growth Accelerator applies directly.
Establishes where time, margin and revenue really come from: which clients, which services, which partners. Most firms are surprised by the answer.
Strips out the non-billable activity and service line sprawl that drains capacity.
Tackles pricing and delivery, so fees reflect value rather than hours.
Focuses investment on the clients and services already proven to be most profitable.
Turns business development into an accountable process rather than a hopeful one.
Analysis powered by our AI Growth Engine, judgement led entirely by our consultants, including the harder conversations with partners about what needs to change.
Where is the time and margin in your firm really going?
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