Almost every UK accounting firm sets a utilisation target somewhere between 75% and 85%. Most do not hit it. The interesting question is whether they should be trying. The data from firms that consistently exceed 80% utilisation is not flattering: more write-offs, lower realisation, higher staff turnover, and partner burnout at predictable intervals.
What utilisation actually measures
Utilisation is chargeable hours divided by available hours. If a senior bills 32 hours in a 40-hour week, utilisation is 80%. The metric was imported from law firms in the 1980s and lifted wholesale into accounting. It rewards activity, not outcomes. A senior can bill 38 hours of recoverable time and still hand the firm a £4,000 write-off because the work was over-engineered or mispriced.
Utilisation tells you how busy people are. It does not tell you whether the work was profitable, whether the client was satisfied, or whether the team will still be there in six months.
The chase that bites back
Firms that publicly target 80%+ utilisation create predictable behavioural patterns. Staff pad timesheets - they record 8 hours to a job because they were "thinking about it" between actual work. Seniors stop investing in juniors because mentoring is non-chargeable. Quality reviews get shortened. Holiday gets cancelled in busy periods because the target eats into the buffer.
The most damaging effect is silent: when utilisation becomes the success metric, partners stop hiring at the right pace. Why hire a sixth senior when the five you have are at 82%? Because the next 8% of work goes onto someone already at the ceiling, and the work that gets dropped is the partner's strategic thinking, not the client work.
The 70% sweet spot
Sustained healthy utilisation across an accounting team sits around 65-70% of contracted hours, once you factor in honest holidays, CPD, internal admin, and the natural week-to-week variance. Push higher than that for a quarter and you can sustain it. Push higher for a year and you start losing people.
Firms running at 68% utilisation with 92% realisation make more money than firms running at 82% utilisation with 84% realisation, with calmer staff and lower recruitment costs. The maths is uncomplicated but the cultural shift required to accept it is real.
Better metrics, properly weighted
If you stopped reporting utilisation tomorrow and replaced it with four numbers, you would have a clearer picture: realisation rate (what percentage of recorded time becomes billed), write-off ratio (recorded hours not billed, by partner), free capacity over the next 13 weeks (sellable hours available), and average days from job-close to invoice (the lockup precursor).
These metrics surface the things that actually move profitability - pricing discipline, scoping, billing speed, capacity for new work - without rewarding the bums-on-seats behaviour that high utilisation targets produce.
What to do with the freed dashboard space
Drop firm-wide utilisation off the management dashboard. Replace it with grade-specific free capacity for the next 90 days. Practice-management tools like Accupe surface this directly from time bookings, planned jobs, and known absences. The conversation in the management meeting shifts from "why is utilisation only 73%" (a backwards-looking blame conversation) to "we have 320 hours of senior capacity in May, what do we want to do with it" (a forward-looking decision conversation).
The exception: short, contained pushes
There is a place for high utilisation. A four-week busy-season push at 90% utilisation, with explicit recognition and recovery time after, is sustainable and sometimes necessary. The damage comes from making 80%+ the steady-state target. Treat very high utilisation the way you treat overtime - occasional, paid for, and followed by recovery, never the default.
What partners actually need to track
The partner-level dashboard for a healthy firm looks like this: realisation by client segment, lockup days by partner, free capacity over a rolling 13-week horizon, write-off ratio against pricing model, and staff retention by tenure band. None of these are utilisation. All of them predict profitability and stability better than the metric they replace.
Closing
Utilisation is the EBITDA of practice management: easy to measure, widely cited, and a poor proxy for the thing you actually care about. Replace it with metrics that reward profitable, sustainable delivery, and the firm tends to follow.