Originally published on LinkedIn on 23 July 2026.
The Law Society’s latest Financial Benchmarking Survey 2026 brought good news. Average lock-up across UK law firms fell to 134 days, down from 146 the year before. Chargeable hours per fee earner rose too, climbing to 807. For firms that have spent years tightening billing cycles, chasing debtors, and reviewing WIP on a schedule, this is the number that says the work paid off.
That improvement doesn’t tell the whole story. A falling average doesn’t mean the underlying risk has declined. Unless checked, the opposite can be happening underneath it. Work goes unbilled, gets disputed, or is quietly written off entirely. Every pound written off is profit the firm already paid to produce, and will never see.
The average is improving. The margin behind it may not be. This article shows you how to recognise that gap in your own firm, before your numbers do.
Why the risk hasn’t moved with it
Independent research from BigHand, surveying over 800 senior finance and legal leaders across the UK, North America, and Ireland, found that aged WIP is now the primary driver of cash-flow pressure for half of firms surveyed, up from a third the year before. Write-offs have increased at nearly nine in ten firms, and most expect a further rise.
UK accountancy firm Kreston Reeves, which advises law firms directly on lock-up management, makes the same point. WIP often accumulates not for genuine commercial reasons but through delayed billing decisions, and the longer it sits unbilled, the higher the risk of disputes, discounts, and write-offs.
Two independent sources, one in the sector’s own data and one in its advisory practice, and both point to the same thing: risk can grow even while the headline lock-up figure improves. A falling average and a rising risk can be true at once. The average measures cash. It does not measure exposure.
What you would have noticed before the report does
So, what does that exposure actually feel like from a managing partner’s chair?
It rarely arrives as a single alarming number. More often it shows up as five smaller, quieter signals:
1. The lock-up figure says things are improving, but your own sense of financial control has not caught up with the number.
-
A specific type of problem keeps resurfacing, not with one partner but across several, and each time it looks like an isolated incident rather than a pattern.
-
Two teams run the same billing software and follow the same process. One team’s matters rarely age or need writing off. The other’s regularly do. If the tools and the process are the same, something else is producing that gap.
-
A write-off or a client complaint lands, and when you trace it back, the early warning signs were visible to the team for weeks before anyone told you.
-
There is a familiar fatigue in fixing the same thing every year: another WIP push, another billing tightening, a short-term improvement, then a slow drift back to where you started.
None of these five signals will appear in a lock-up report, because a lock-up report only measures what has already happened. It cannot measure the risk still forming behind it.
The evidence underneath the numbers
There is real evidence that leadership behaviour is part of what shapes this risk. A 2008 statistical study by McBassi & Co found that the strongest predictor of a law firm’s profitability was the quality of partners’ leadership skills, specifically the ability to set direction, build consensus, and reinforce values, alongside managerial skill in ensuring work is delivered the way clients expect.
Nearly a decade later, Stanford Law Review cited the same finding in its own review of leadership research, still describing it as the most powerful predictor identified in the field.
That doesn’t mean leadership behaviour explains every ageing matter. Resourcing and structural issues can also be a factor however what the research does show is that leadership pattern is one of the most significant, and least measured, factors behind a firm’s financial performance. A benchmarking survey has no way to capture it, and yet it shapes what that survey will eventually show.
The layer nobody’s tracking
Clio, Aderant, and similar platforms can break down aged WIP by matter, by client, and by the fee earner responsible, some will even flag anything sitting unbilled past a set number of days. A firm that wants to see which matters are ageing, and under which partner, usually can, with a report that already exists.
What the system cannot tell you is why. A partner’s matters ageing longer than their colleagues’ could mean several different things, and none of them are visible from the report alone. It could be a deliberate commercial decision, a client not yet ready to be billed. It could be a resourcing problem sitting above the partner entirely, an approval step stuck elsewhere in the firm. Or it could be a partner who reviews everything personally and has simply run out of room to do it in time.
The report shows the symptom. It was never built to tell you why any of these is actually happening, and the answer changes what you’d do about it.
The cost compounds either way. A write-off isn’t lost revenue in the abstract. It’s work the firm already paid to produce, salaries, time, overhead, with nothing recovered against it.
Which of the five have you felt?
Which of these five have you felt this year? The gap between the number and your own sense of control. The pattern that keeps resurfacing under different names. The two teams with identical tools and different results. The problem you found out about too late, or the fatigue of fixing the same thing again. Knowing it will need fixing again next year.
Most managing partners will recognise at least one of these five signals in their own firm. Knowing that a signal is present is not the same as knowing its cause. Few currently have a reliable way to tell whether they are looking at a deliberate commercial decision, a resourcing gap, or a partner who has simply run out of capacity to review everything in time.
Every one of these causes has a different fix. Guessing wrong costs you twice, in time and in money. The Financial Diagnostic tells you which operational patterns are actually costing you margin. It’s free, and takes ten minutes.