Working Time Regulations: Getting It Right (UK Employers)

Rest breaks, the 48-hour week, and the rules people quietly get wrong

If you run a small business, the Working Time Regulations are one of those things that sit in the background quietly working fine, right up until they don't.

Usually it surfaces as a question you weren't expecting. "Can you make me work twelve days straight?" Or a night-shift worker asking why nobody ever checked they were fit to do nights. Or you, at 11pm, wondering whether the 48-hour week is a hard cap or an average, and whether anyone can actually agree to work more.

This is the plain-English version. What the law actually asks of you, the bits people get wrong, and what to write down so a disagreement never turns into a dispute.

Hazel (our Chief Wellbeing Officer) is firmly pro rest break. Her view is that 20 minutes minimum should apply to humans and that a nap should count. We're working on her.

Quick Answer Box

• Do this: respect the rest breaks, treat the 48-hour week as a 17-week average, and get any opt-out in writing.
• Avoid this: making an opt-out a condition of the job, ignoring night work health checks, or assuming the under-18 rules are the same as everyone else's.
• Write down: working patterns, any signed opt-outs, and a record of hours so you can show you are within the limits.

What the law actually says

The rules come from the Working Time Regulations 1998. They set out the maximum hours people can be asked to work, the rest they must get, and extra protection for night workers and young workers.

The headline points for a small employer are:

• a limit on average weekly working hours
• daily and weekly rest
• a rest break during the working day
• paid holiday
• stronger limits for night workers and under-18s

None of it is especially complicated on its own. The trouble usually comes from treating one rule (like the 48-hour week) as something it isn't.

Official guidance: gov.uk maximum weekly working hours

The 48-hour week (it's an average, not a daily cap)

This is the one people most often misread.

Workers should not work more than 48 hours a week on average. That average is normally measured over a 17-week reference period. So a busy week of 55 hours isn't automatically a breach, as long as it balances out across the 17 weeks.

A worker can choose to opt out of the 48-hour limit. The opt-out has to be:

• voluntary
• in writing
• something they can later cancel by giving notice

The bit employers get wrong: you cannot make signing the opt-out a condition of getting the job, and you cannot pressure someone into it. It has to be a genuine choice. Always check the current notice period for withdrawing an opt-out on gov.uk before you rely on it.

One important exception: night workers cannot opt out of the separate night work limit (more on that below).

Daily rest, weekly rest, and the 20-minute break

Three rest entitlements sit at the heart of the regulations. For most adult workers:

• A rest break: at least 20 minutes when the working day is longer than 6 hours. They should be able to leave their workstation and not be on call during it, and it shouldn't be tacked onto the very start or end of the day.
• Daily rest: 11 consecutive hours of rest in each 24-hour period. So if someone finishes at 9pm, they shouldn't be starting again until 8am.
• Weekly rest: 24 uninterrupted hours off each week, or 48 hours off each fortnight.

You don't have to pay for the 20-minute break, and you don't have to provide extra tea or smoking breaks on top. Many employers pay it anyway. Whatever you choose, make it consistent and write it down.

Some roles (shift work, jobs a long way from home, round-the-clock cover, genuine emergencies) may qualify for compensatory rest instead, where the missed rest is taken as soon as possible afterwards. The detail varies, so check the rules for your situation rather than assuming an exemption applies.

ACAS guidance: rest breaks at work

Night workers (the part that's easy to forget)

If you have genuine night workers, there are extra duties.

A night worker is, broadly, someone who regularly works at least 3 hours during the night period (normally 11pm to 6am). For them:

• normal night working hours should not exceed an average of 8 hours in any 24-hour period, again measured over a reference period
• regular overtime counts towards that limit
• they cannot opt out of the night work limit
• you must offer a free health assessment before they start night work and on a regular basis after that

That health assessment is the one most small employers miss. It doesn't need to be elaborate, but it does need to happen and be recorded.

GOV guidance: night working hours

Young workers (under 18) get stronger protection

Workers over school leaving age but under 18 have tighter limits. As a general guide:

• a 30-minute rest break if they work more than 4.5 hours
• 12 hours of daily rest
• 48 hours of weekly rest
• lower weekly hour caps than adults

Always check the current under-18 limits on gov.uk before setting a young worker's hours, because they differ in important ways from the adult rules and have a few specific exceptions.

GOV guidance: young people and work

Holiday is part of this too

The Working Time Regulations are also where statutory paid holiday comes from. The minimum is 5.6 weeks of paid holiday a year, which works out as 28 days for someone working five days a week.

Part-time staff get the same 5.6 weeks, pro-rated to their pattern. If you've ever lost an afternoon to that maths, we've written it up properly here: how to calculate annual leave for part-time employees. And once you've nailed the entitlement, the next puzzle is what to pay for it, which we cover in how to calculate holiday pay.

And a quick word of warning from a classic small-business trap: if your leave year runs 1 April to 31 March and your contracts say "20 days plus bank holidays", an odd year where a bank holiday falls outside your leave year can leave someone below 28 days without anyone noticing. The fix is to define the entitlement as a total number of days rather than "X plus bank holidays", so the statutory minimum is always met.

GOV guidance: holiday entitlement rights

Keeping records (the bit that's tightening)

You're expected to keep adequate records to show you're meeting the limits, particularly the 48-hour week and night work.

This is an area to watch. A European court ruling pushed employers towards keeping objective, reliable records of daily working time, and record-keeping duties around working time and holiday are expected to be strengthened further under upcoming reforms. The exact requirements may have moved by the time you read this, so treat record-keeping as something to tighten rather than relax, and check current gov.uk guidance before you rely on a minimum.

The practical takeaway doesn't change: if you can't show what hours someone worked, you can't show you stayed within the law.

A short example

Sam manages a small café with a couple of late finishers and one early opener.

One employee, Priya, regularly does 50-hour weeks in summer. That's fine as long as her average across the 17-week reference period stays at or under 48, or she has signed a voluntary opt-out. Sam gets the opt-out in writing rather than assuming, and notes that Priya can cancel it.

A second employee, Jordan, does the 5am bakery shift, which runs into the night period. Sam realises Jordan counts as a night worker, offers a free health assessment, keeps his average night hours within the 8-hour limit, and notes that Jordan cannot opt out of that limit.

Nobody's hours actually changed. What changed is that Sam can now show the rules were followed.

Common mistakes (and the fix)

• Mistake: treating the 48-hour week as a hard weekly cap.

- Fix: it's a 17-week average. Look at the average, not a single busy week.

• Mistake: making an opt-out a condition of the job.

- Fix: it must be voluntary, in writing, and cancellable.

• Mistake: forgetting night worker health assessments.

- Fix: offer one before night work starts and regularly after, and record it.

• Mistake: applying adult rules to under-18s.

- Fix: young workers have stronger break and rest entitlements. Check them.

• Mistake: "20 days plus bank holidays" wording that can dip below 28 days.

- Fix: define holiday as a total number of days so you always meet 5.6 weeks.

• Mistake: no records of hours.

- Fix: keep enough to prove you're within the limits.

What to write down

For each worker, make sure you can show:

• their normal working pattern and contracted hours
• any signed 48-hour opt-out, and that it was voluntary
• night worker status and the date of their last health assessment
• rest break arrangements (and whether breaks are paid)
• holiday year dates and entitlement as a total number of days
• a record of hours worked, kept long enough to be useful in a dispute

Bottom line

• the 48-hour week is an average over 17 weeks, and opt-outs must be voluntary and in writing
• rest breaks, daily rest, and weekly rest are minimums, not nice-to-haves
• night workers and under-18s get extra protection that's easy to overlook
• statutory holiday is 5.6 weeks, and your contract wording must always meet it
• keep records, and expect record-keeping duties to tighten

Right, what do you do now?

If you're not certain your opt-outs are valid, your night work is covered, or your contract holiday wording always hits the statutory minimum, that's exactly the sort of thing we pick up in an HR Health Check.

No judgement, just a clear view of what's solid, what's risky, and what to fix first.

Book your HR Health Check here: Free HR Health Check

Or if you'd rather talk it through first, book a discovery call.