The 48-hour week, rest breaks and opt-outs: what the working time rules actually require

A small employer usually meets the Working Time Regulations for the first time in the middle of an argument. Someone has been doing sixty-hour weeks through a busy spell. A member of staff has worked eight days straight and said something about it. Or an employee asks whether they are actually entitled to a lunch break, and nobody in the building knows the answer.

The rules themselves are not complicated. They are just rarely read until the moment somebody needs them. Here is what the Working Time Regulations 1998 require, in roughly the order the questions come up.

The 48-hour week is an average, not a weekly cap

The most common misunderstanding is that a worker cannot work more than 48 hours in any one week. What the rules actually say is that a worker should not work more than 48 hours a week on average, normally averaged over a 17-week reference period. A single 60-hour week during your busiest fortnight is not, on its own, a breach of anything.

Work it through on a real rota. Suppose a member of staff does 55 hours a week through eight weeks of a busy summer and 40 hours in the other nine weeks of the 17-week period. That is 440 hours plus 360, so 800 hours over 17 weeks, an average of 47.1 a week. Inside the limit, no opt-out required. Now stretch the busy spell: twelve weeks at 55 and five at 40 gives 860 hours, an average of 50.6 — over the limit, and you have a problem you did not have four weeks earlier.

One subtlety catches people out. Paid annual leave and sickness absence are not treated as convenient low weeks that pull the average down. Those days are excluded from the calculation and replaced by the hours actually worked in the days immediately following the reference period. A fortnight in Spain does not buy you two months of overtime.

The opt-out is voluntary, individual and cancellable

A worker can agree to work more than an average of 48 hours. The agreement must be voluntary and in writing, and it can run for a set period or indefinitely. Keep the signed record, because that record is the entirety of your evidence that the agreement exists.

Three constraints matter more than the agreement itself. The opt-out belongs to the individual, not to the job, so you cannot opt out a role, a shift pattern or a department. A worker can cancel whenever they like, giving at least seven days' notice, or up to three months if that is what the agreement specifies. And you cannot require anyone to sign: a worker cannot be dismissed or treated unfairly for refusing, which makes "sign this or there is no work for you next week" both unlawful and an expensive sentence to have said in front of witnesses.

Some roles cannot opt out at all — airline staff, workers on ships and boats, road transport workers including most delivery drivers, staff covered by EU drivers' hours rules, and security workers transporting high-value goods. If you run vans, establish which set of rules applies to your drivers before you rely on an opt-out that does not exist for them.

The 48-hour limit is the one part of the working time rules you can contract out of. Everything below it, you cannot.

Rest breaks and rest periods, where there is no opt-out

An adult worker who works more than six hours a day is entitled to one uninterrupted 20-minute rest break during the working day. Uninterrupted is the operative word. A break during which someone is expected to answer the phone, keep an eye on the shop or stay within reach of the till is not a rest break, and "they eat when it goes quiet" is not a system. Whether the break is paid is a matter for the contract — the law requires the break, not the pay for it.

Between working days, a worker is entitled to 11 consecutive hours of rest. Finish at 8pm and the next shift should not start before 7am, which is what makes a close-then-open rota a compliance question rather than merely an unpopular one. Each week, a worker is entitled to an uninterrupted 24 hours without any work, or 48 hours in each fortnight. So an eight-day run is possible in principle. A fourteen-day one is not.

Night workers and under-18s have their own rules

Someone who regularly works at least three hours during the night period — normally 11pm to 6am, unless you and the worker agree a different one — counts as a night worker. Night workers should not work more than an average of eight hours in any 24-hour period, usually averaged over 17 weeks, or up to 52 weeks by agreement. You must also offer a free health assessment before they start night work and at regular intervals afterwards. Offering it is your duty; taking it up is their choice, and a note of the offer is worth keeping.

Workers over school leaving age but under 18 have stricter and separate entitlements: no more than 8 hours a day or 40 hours a week, with no averaging and no opt-out; a 30-minute break if they work more than 4.5 hours; 12 hours of daily rest; and 48 hours of weekly rest. Sixteen and seventeen year olds generally cannot work between 10pm and 6am (or 11pm and 7am if the contract sets it that way), and cannot work between midnight and 4am at all, with limited exceptions in sectors including agriculture, hospitality, retail and healthcare.

Four things to do this week

Pull the last 17 weeks of hours for anyone who regularly works long weeks and work out the actual average. Most owners guess, usually wrongly in whichever direction suits them, and the real number tends to end the argument either way.

Check whether the people running over 48 hours have signed opt-outs, and whether you could lay hands on them today. An opt-out you cannot produce is an opt-out you do not have.

Look down your rota for close-and-open shifts and runs of twelve days or more. Those two patterns breach daily and weekly rest more often than anything else, and neither one looks like a problem on the rota sheet.

Write the break policy down: how long, when it is taken, whether it is paid, who covers. Half of all disputes about breaks are really disputes about the absence of any rule.

Keeping adequate records is itself part of the duty — you need to be able to show that workers without an opt-out are not exceeding the limit. If your hours live in a WhatsApp group and one manager's memory, you do not have records. A retained rota is enough, and it is about the cheapest insurance available in employment law. If you are hiring for the first time, what actually needs to be in a written employment contract is the other half of this job. If the hours question has come up because someone else is off, managing staff sickness absence is usually where it leads next, and how much holiday your staff are actually entitled to is the question that follows that one.

Common questions

Is the 48-hour working week a hard weekly limit?

No. The rule is that a worker should not work more than 48 hours a week on average, normally averaged over a 17-week reference period, so a single long week is not a breach in itself. Eight weeks at 55 hours followed by nine weeks at 40 averages 47.1 hours and stays inside the limit; twelve weeks at 55 and five at 40 averages 50.6 and does not. Paid annual leave and sickness absence are not counted as low weeks that drag the average down — those days are excluded and replaced by hours worked in the days immediately after the reference period.

Can I ask my staff to sign a 48-hour opt-out?

You can ask, and many workers sign, but the agreement has to be genuinely voluntary and in writing, and it applies to the individual rather than to the job or shift pattern. You cannot dismiss or disadvantage someone for refusing, so making work conditional on signing is unlawful. A worker can cancel the opt-out at any time by giving at least seven days' notice, or up to three months if the agreement says so. Some workers cannot opt out at all, including airline staff, workers on ships, most road transport workers and security staff transporting high-value goods.

Do I have to pay staff for their 20-minute rest break?

Not unless the contract says so. The law entitles an adult worker who works more than six hours a day to one uninterrupted 20-minute break during the working day, but it does not require that break to be paid — whether it is paid is a matter for the employment contract. What the law does require is that the break is genuinely uninterrupted and taken during the working day, not added to the start or end of a shift. A break where someone is expected to cover the phone, watch the shop or stay on call is not a rest break, whether or not you are paying for it.

What working time records does a small employer have to keep?

You need to keep adequate records to show that workers who have not signed an opt-out are not exceeding the 48-hour average, plus records of any signed opt-out agreements and of the free health assessments offered to night workers. There is no prescribed form. A retained rota or timesheet system, kept for a couple of years, generally does the job. Hours recorded only in a WhatsApp group or a manager's memory do not, and the absence of records tends to matter most in exactly the situation where you need them — a complaint, a grievance or an inspection.