Analysis of professional-services time tracking puts the range starkly: firms typically capture only 72 to 95% of the billable hours their people actually work. That gap is not a rounding error. In a 100-person consultancy, losing just 45 minutes of untracked time per person per week is enough to write off over £1 million in annual revenue — money that was earned, delivered and then simply never recorded.
For UK AEC consultancies running on the margins the sector has grown used to, that figure is not an abstract benchmark. It is roughly the difference between a healthy year and a nervous one. This article looks at where the leakage actually happens, why the usual explanations ("people are bad at timesheets") miss the point, and what a firm can realistically do about it without turning every fee earner into a stopwatch operator.
Why untracked billable hours matter for UK firms right now
Start with the arithmetic, because it is the part most firms have never done. Forty-five minutes a week sounds trivial. Nobody would raise it at a board meeting. But across 100 people and a working year it becomes thousands of hours, and at professional-services charge-out rates those hours are worth more than £1 million. The reason it never reaches the board is precisely that it never appears anywhere: no invoice, no write-off, no variance report. It is revenue that leaves without leaving a trace.
The 72 to 95% capture range is the more revealing number, because it describes the same profession doing the same work with wildly different results. The difference between the bottom and the top of that range is not talent, effort or client mix. It is process. Firms at 95% have made recording time close to frictionless and made it a normal part of the working day. Firms at 72% still rely on Friday-afternoon reconstruction from calendars, email and memory, which reliably rounds down.
Two UK-specific pressures make this urgent rather than merely interesting. First, margins in AEC consultancy remain thin enough that a few percentage points of unrecorded time is the difference between a profitable project and a break-even one. Second, clients have become far more forensic. Fee negotiations, variation claims and disputes increasingly turn on whether the consultant can evidence the effort behind the invoice. Billable hours tracking has quietly moved from an internal admin function to a commercial defence, and a firm at 72% capture is walking into those conversations without its evidence.
Key takeaways
- Professional-services firms typically capture only 72 to 95% of billable hours actually worked.
- A 100-person consultancy losing 45 minutes of untracked time per person weekly writes off over £1 million in annual revenue.
- The gap between 72% and 95% capture is a process problem, not a people problem.
- Retrospective timesheets reliably round down, because memory rounds down.
- Unrecorded time is invisible revenue leakage: no invoice, no write-off, no variance report, no board discussion.
What this means for AEC and professional-services consultancies
For directors and owners, the important reframing is that this is not a collections problem or a pricing problem. It is a measurement problem that presents as both. If your firm sits at 85% capture, then roughly one hour in seven of genuinely chargeable work never makes it onto an invoice. Raising fees will not recover it. Chasing debtors will not recover it. The only thing that recovers it is capturing it at the point the work happens, which is a software and habit question rather than a commercial strategy one.
For project leads and associates, the leakage is concentrated in exactly the work that feels too small to record. A fifteen-minute call with a client about a variation. Twenty minutes reviewing a subcontractor's submission between two meetings. A quick sketch to answer a site query. None of it feels like a billable event at the time, and by Friday none of it is remembered. Yet on a typical week it adds up to the 45 minutes that costs the firm seven figures across a hundred people. Good time tracking software for architects and engineers makes those fragments cheap to record; poor systems make them expensive enough to skip.
For finance and operations leads, there is a second-order effect that is arguably worse than the lost revenue. Incomplete timesheets do not just under-bill; they corrupt every number built on top of them. Project profitability looks better than it is, because costs are understated. Utilisation looks lower than it is. Fee proposals for the next similar project are built on hours that were never fully recorded, so the firm systematically underprices work it has already done. Resource management software forecasting from bad actuals produces confident, precise, wrong answers.
Your fee benchmarks are wrong
If historic projects captured 80% of the real hours, every fee proposal built from them is priced for a job that took less time than it did. The error compounds with each bid.
Friction is the whole battle
Capture rates track almost perfectly with how long it takes to record an hour. Mobile entry, sensible defaults and prompts beat policy reminders every single time.
Disputes need evidence
Variation and scope arguments are won with a dated, contemporaneous record of who did what. Reconstructed timesheets are worth very little when a claim gets serious.
How UK consultancies capture billable time today
Most firms are running one of three setups: a spreadsheet template emailed round on Fridays, a standalone time tracking app that does not know about fees, or an integrated practice management system. All three record hours. What separates them is whether those hours arrive in time to change anything, and whether they connect to the fee they are supposed to be earning against.
| What you need | Spreadsheets | Point tools | Quantim |
|---|---|---|---|
| Low-friction daily capture | Entry happens on Friday from memory, so short tasks disappear entirely. | Standalone timers work well, until people forget to start or stop them. | Timesheets are quick to complete daily against live projects and stages. |
| Hours linked to the fee | Two files, joined by hand, usually a fortnight after the month closed. | Time apps record hours; they rarely know the fee or the stage budget. | Recorded time posts straight against project, stage and fee in one model. |
| Visible capture rate | Nobody calculates it, so nobody knows whether it is 72% or 95%. | Reported per user at best, and disconnected from chargeable capacity. | Recorded versus available hours is visible by person, team and period. |
| Billing without a scramble | Days of chasing, copying and reformatting before invoices can be raised. | Export, reformat, reconcile, then re-key into the finance system. | Approved time flows into billing, so invoicing is a review rather than a rebuild. |
| Forecasts built on real actuals | Forecast lives in a separate sheet and rarely reconciles to what happened. | Planning tools exist, but seldom compare plan against recorded time. | Resource forecasts and recorded actuals share one model, so variance is weekly. |
How Quantim helps
This is the most directly quantifiable case Quantim makes. Timesheet and billing functionality is not a productivity nicety here; it is a revenue recovery mechanism with an arithmetic anyone can check on the back of an envelope. Work out your headcount, your average charge-out rate and your realistic capture rate, and the annual value of closing the gap falls out in about two minutes.
What makes the difference is where the timesheet sits. Quantim records time against live projects, stages and fees rather than into an isolated app that has to be reconciled later, so an hour booked on Tuesday is visible in project performance on Tuesday. That closes the loop between billable hours tracking, resource management and invoicing: capture improves because entry is quick and contextual, and the improvement immediately shows up in what can actually be billed.
- Measure your capture rate before you change anything. Compare recorded hours against available chargeable hours for a full quarter, by team. Until you know whether you are nearer 72% or 95%, you are guessing at the size of the prize.
- Remove the friction, not the flexibility. Make daily entry take under two minutes, with recent projects and stages one tap away. Capture rate follows ease of entry far more reliably than it follows policy.
- Close the loop into billing and forecasting. Feed approved time straight into invoicing and into the next fee proposal, so recovered hours become invoiced revenue and better-priced future work rather than a nicer-looking report.
Find out what your firm's real capture rate is — and what closing the gap would be worth in invoiced revenue.
Request a demoUntracked time is the only revenue leak in a consultancy that never appears on a report. You do not write it off. You simply never see it arrive.
"We assumed our timesheets were basically accurate because everyone submitted them. Then we compared recorded hours against available chargeable hours across a quarter and found we were sitting in the low eighties. Nobody was being dishonest — they were reconstructing four days of work on a Friday afternoon. Moving to daily entry recovered more revenue in six months than our last fee increase did."
Finance Director, engineering consultancy, Bristol
Checklist for firm leaders
- Calculate your actual capture rate: recorded chargeable hours against available chargeable hours, for a full quarter, by team.
- Run the arithmetic on your own headcount and charge-out rates so the value of the gap is a number, not a worry.
- Time how long it takes one of your people to complete a day's timesheet, and treat anything over two minutes as a design fault.
- Move from weekly reconstruction to daily entry, with mobile capture for site visits, calls and short client tasks.
- Check that recorded time posts against project, stage and fee, so it feeds billing and forecasting without manual joining.
- Review capture rate as a standing management report alongside utilisation and work in progress, not once a year.
Frequently asked questions
How much revenue do untracked billable hours actually cost a firm?
More than most leadership teams expect, because the loss is invisible by definition. Analysis of professional-services time tracking finds firms typically capture only 72 to 95% of the billable hours their people work. Applied to a 100-person consultancy, losing 45 minutes of untracked time per person per week is enough to write off over £1 million in annual revenue. The arithmetic is simple to run for your own firm: multiply headcount by weekly lost minutes by working weeks by your blended charge-out rate. The underlying analysis is published by Rocketlane.
What should UK professional-services firms look for in timesheet software?
Prioritise three things, in this order. First, speed of entry: if recording a day takes more than a couple of minutes, capture will drift downwards no matter what the policy says, so mobile entry and one-tap access to recent projects matter more than any feature list. Second, connection to the fee: hours that post directly against project, stage and budget are useful immediately, whereas hours sitting in a standalone app need reconciling before they mean anything. Third, whether the same data drives billing, utilisation and resource management software forecasting, because that is what turns better capture into invoiced revenue rather than a tidier spreadsheet.
Does time tracking software work as well for construction firms as for consultancies?
Yes, and arguably the case is stronger, because construction and AEC teams work across more locations and more fragmented tasks than a purely office-based consultancy. Site visits, travel, short site queries and out-of-hours calls are precisely the fragments that never survive a Friday-afternoon reconstruction. What matters is that the system handles the realities of construction delivery: mobile capture away from a desk, time booked against project stages and work packages rather than vague cost codes, and a direct route from approved hours into billing and cost reporting. The same principles apply to time tracking software for architects, engineers, quantity surveyors and contractors alike.
Every consultancy has a capture rate. Very few know what theirs is, and the ones that find out are usually surprised in an expensive direction. Closing the gap between 72% and 95% is not a cultural project; it is a matter of making the right thing take less time than the wrong one. Explore the features and benefits that help UK AEC firms capture, bill and forecast every hour they actually work.