No sector tests the four-day week like a law firm, because the product has historically been an hour. If clients buy time, and staff have less of it, something in the model has to give. The firms exploring shorter weeks are discovering that what gives is not quality — it is the assumption that every hour billed was ever the same as value delivered.
A note on evidence, in the spirit of this series: there is no large, published four-day pilot of law firms comparable to the UK’s 61-organisation trial of 2022. What follows draws on that wider professional-services evidence and on the design problems firms themselves report. Treat it as a playbook, not a result.
Re-base utilisation before you touch the week
Utilisation targets built on a 40-hour week become quiet sabotage on a 32-hour week. If a fee-earner’s target hours stay fixed while available days fall, you have designed a four-day week that must be worked in secret — the pattern behind several documented reversals in other sectors, where staff simply worked the fifth day invisibly and burned out.
So the first act is arithmetic, done openly: re-base annual chargeable targets to the new week, state what happens to non-chargeable expectations (business development, training, supervision), and decide how leverage and write-offs will be judged during the pilot. Partners who skip this step get a pilot that looks calm and a workforce quietly working Fridays.
Coverage is a client promise, not a rota
Clients fear one thing: my matter stalls because my lawyer is off. Courts, closings, and counterparties do not observe your pilot. The design answer is the same one that works in agencies and support desks — sell and staff the service, not the individual.
Map demand by day: court deadlines, completion days, client committee cycles. Stagger days off away from a practice group’s peak, pair fee-earners as named cover for each other, and write the cover arrangement into client communications before launch: your lead, your cover, our response commitment. Urgent-work rotas should be explicit and compensated, not a permanent on-call shadow that erases the day off for junior staff. If the day off is conditional on checking in, say so, price it, and expect a smaller wellbeing gain — the UK pilot’s conditional variants showed exactly that trade-off.
Trainees and junior lawyers need deliberate protection: supervision, file exposure, and mentoring do not happen by osmosis in a thinner office. Build paired working and scheduled review time into the four days, or the pilot will quietly tax the people least able to object.
Talk value before clients make you talk price
The feared conversation — “if you work four days, why does the fee stay the same?” — is easier before the pilot than during it. Most clients, asked early, care about responsiveness, continuity, and outcomes; several professional-services firms in the wider pilots found clients neutral-to-positive once service levels were evidenced. The firms in trouble are the ones whose clients discover the change from an out-of-office reply.
Where the model allows, use the pilot to pilot pricing honesty too: fixed or capped fees for defined stages, so the client’s interest and the firm’s stop being opposites. Even where hourly billing remains, share month-one and month-three service data — response times held, deadlines met — rather than asking clients to take the week on faith.
The scorecard for a firm
Outputs: matters progressed and completed, deadlines met, realisation and write-offs. Quality: errors, complaints, file-review findings. Customer: response times and client satisfaction. People: actual hours (including the fifth day), burnout pulses, resignations in a profession with a retention problem worth solving. Finance: revenue per fee-earner and per hour, so intensification cannot hide inside a good quarter.
Law may be late to this evidence base, but its economics point the same way as the pilots’: experienced lawyers are scarce, clients buy judgement rather than attendance, and judgement is the first thing fatigue takes. Design the week around that, and measure like you mean it.
Sources
- Autonomy, University of Cambridge and Boston College, UK Four-Day Week Pilot results (February 2023) — professional-services firms within the 61-organisation cohort.
- 4 Day Week Global, US and Ireland pilot results (December 2022).
- University of Münster, Intraprenör and 4 Day Week Global, Germany four-day week pilot results (October 2024).
Day5Group is a consultancy that assists in the transition to a 4 day work week. More about Day5Group · All blog articles