Is Working 70 Hours A Week Legal In The UK?

If your business is growing fast or operating around the clock, you might be wondering where the legal lines are on long hours. Is working 70 hours a week legal in the UK, and how do you schedule shifts without breaching the rules?

In short: long weeks can be lawful in some cases, but there are strict limits around average weekly hours, rest breaks, night work and vulnerable workers. Getting this wrong can lead to fines, tribunal claims and-most importantly-real health and safety risks for your team.

Below, we break down what the law requires and share practical steps to manage longer working patterns responsibly and compliantly.

What Does UK Law Say About Maximum Working Hours?

The main rules sit in the Working Time Regulations 1998 (WTR). As a starting point, adult workers must not work more than an average of 48 hours per week-averaged over a reference period (typically 17 weeks). That average is key. So a single 70-hour week isn’t automatically unlawful, but consistently scheduling 70-hour weeks is very likely to breach the average unless you have a valid opt-out and you’re still meeting all rest rules.

Key points for employers:

• 48-hour average weekly limit over a reference period (usually 17 weeks).
• Workers can choose to opt out of the 48-hour average weekly limit, but it must be voluntary, in writing, and workers can withdraw their consent with notice.
• Even with an opt-out, you must still comply with daily and weekly rest, rest breaks, night work limits, and health and safety duties.

For a deeper dive into employer obligations, opt-outs and record-keeping, it’s worth reviewing the Working Time Regulations and how the limits and opt-outs work in practice. You can also make these rules clear in your Employment Contract and policies so everyone understands how hours will be managed.

Remember that some roles are subject to different rules (for example, certain mobile workers in transport), and limited exemptions apply to workers with autonomous decision-making where working time can’t be measured or predetermined. If you’re unsure whether an exemption applies, get tailored advice.

How Many Hours Can Someone Work In A Day?

There isn’t a single, universal “daily maximum” in UK law for all workers. Instead, the WTR set minimum rest entitlements that effectively limit the length of a lawful shift:

• Daily rest: At least 11 consecutive hours’ rest in each 24-hour period.
• Weekly rest: At least 24 hours uninterrupted each week (or 48 hours each fortnight).
• Rest breaks during work: At least a 20-minute uninterrupted break if the working day is longer than 6 hours.

These rest rules are not optional. They apply even if someone has opted out of the 48-hour weekly average. That means very long single shifts are usually difficult to justify legally because you still need to build in the daily and weekly rest periods.

Make sure you understand your obligations around employee breaks and how they interact with your scheduling model. A long single shift that squeezes rest to the margins is a red flag.

Can Employees Work 70 Hours In A Week?

Here’s the practical answer from an employer’s perspective:

• Possibly, on occasion-if your average across the reference period stays within 48 hours, or the worker has a valid opt-out from the 48-hour average.
• Only if you still meet daily and weekly rest, provide required rest breaks, and stay within any night work limits.
• Never for young workers (under 18) beyond their specific caps (see “Special Rules” below).

Working 70 hours every week on an ongoing basis is rarely compatible with the average weekly limit unless the worker has opted out. Even with an opt-out, excessive long hours can raise serious health and safety concerns. You must assess fatigue risks and take steps to control them. If a worker does not wish to sign an opt-out, they are protected from detriment or dismissal for refusing.

As you design rotas, think in averages and rest. You could, for example, lawfully run a peak week at 60–70 hours if it’s balanced with quieter weeks-provided you still give 11 hours’ daily rest, proper breaks, and a weekly rest period, and you monitor the 17-week average carefully. But if demand means you’re consistently above 48 hours, moving to opt-outs should be a considered, transparent process that puts safety first.

Night work brings its own limits too. If your longer weeks involve night shifts, check the stricter average cap for night workers and the need for health assessments and additional protections associated with night work.

Overtime, Pay And Records: What Are Your Duties?

UK law doesn’t require you to pay a premium rate for overtime (unless your contract or policy promises it), but you must always ensure total pay does not fall below the National Minimum/Living Wage when you divide pay by total hours worked. Also consider how overtime interacts with holiday accrual and working time limits.

From a compliance standpoint, focus on three areas:

1) Contract Clarity

Make sure your Employment Contract clearly sets out working hours, how overtime is authorised, whether it’s paid or time off in lieu (TOIL), and whether a 48-hour opt-out is requested and genuinely voluntary. Avoid vague clauses that suggest “unlimited” hours; they don’t override the law and can cause disputes.

2) Policy And Process

Document the rules for authorising long shifts, managing breaks, and recording hours in your Staff Handbook. This is also where you can outline fatigue management measures, supervisor responsibilities and how opt-out withdrawals will be handled.

3) Record-Keeping

You must keep “adequate” records to demonstrate compliance with the WTR-typically records of hours worked that show you’re within the 48-hour average (unless an opt-out is signed), that night work limits are met, and that rest requirements are being respected. Keep these records for at least two years.

If you offer or require extra hours, ensure your approach to overtime is consistent with the contract. Any wage deductions (for example, for uniforms or training costs) must comply with the rules on wage deductions and never take pay below the minimum wage through unauthorised deductions.

Special Rules You Can’t Ignore

Night Workers

Night workers generally must not exceed an average of 8 hours in a 24-hour period, averaged over 17 weeks (with some variations by sector). Regular health assessments are required and risk controls should be robust. If you’re running extended night shifts, revisit your rota using the rules and guidance around night work.

Young Workers (Under 18)

Young workers cannot work the same long hours as adults. They are usually limited to 8 hours per day and 40 hours per week, with stronger rest protections and limited night work. A 70-hour week is not lawful for this group.

Rest Breaks And Fatigue

Breaks aren’t just a nicety: they’re a legal safeguard. Pressure to skip breaks to “get the job done” can breach the WTR and create safety risks. Build breaks into the rota and empower supervisors to enforce them. Refresh your managers on the rules around employee breaks so practice matches policy.

Health And Safety

Under the Health and Safety at Work etc. Act 1974, you must identify and manage risks-fatigue included. Long hours, night shifts, high-risk environments and lone working all increase fatigue risk. Conduct and document risk assessments for extended shifts and implement control measures (e.g. additional supervision, task rotation, enforced breaks, safe travel home guidance).

Employment Status

Be very clear who is an employee, a worker or genuinely self-employed. WTR protections (and minimum wage, holiday rights, etc.) apply to “workers”, not just employees. If you rely on flexible labour, check your employment status assumptions before scheduling long hours-misclassification is a fast track to claims.

How To Manage Long Hours Lawfully (And Sensibly)

Whether you’re dealing with seasonal spikes or sustained growth, here’s a practical approach to keep you compliant and reduce risk.

1) Plan Around The Average

Build rotas to meet demand without breaching the 48-hour average across the reference period. Use software or simple spreadsheets that flag when individuals are trending over the limit. If your model genuinely requires regular 50–60 hour weeks, implement written opt-outs-voluntarily and transparently.

2) Use Written Opt-Outs Properly

• Make opt-outs voluntary and separate from the job offer decision.
• Explain that workers can withdraw consent, usually with notice (e.g. 7 days, or up to 3 months if agreed).
• Keep signed copies and a clear process to handle withdrawals without penalising the worker.

Even with opt-outs, you must still comply with daily and weekly rest, breaks, and night work limits. Treat the opt-out as one tool in a broader compliance framework, not a free pass.

3) Lock In Rest And Breaks

Design shifts to guarantee the 11-hour daily rest and 24-hour weekly rest (or 48 hours per fortnight). Schedule the 20-minute break for shifts longer than 6 hours and safeguard it operationally. Use clear policy wording in your Staff Handbook so managers know breaks aren’t optional.

4) Manage Night Work Carefully

If you operate at night, reassess shift length, rotation patterns, and recovery time after nights. Offer health assessments and make reasonable adjustments where needed. Ensure your schedules fit within the night work average limit and consider extra controls for safety-critical roles.

5) Clarify Overtime And Pay

Set out how overtime is authorised and compensated. Confirm that total pay divided by total hours never falls below the applicable minimum wage. Align your overtime practice with your Employment Contract and any collective terms. If you use TOIL, document accrual and use-by rules.

6) Keep Adequate Records

Maintain accurate time records that demonstrate compliance with the WTR and your policies. Records should be reliable enough to withstand scrutiny from an enforcement body or tribunal. Keep them for at least two years.

7) Train Managers And Monitor Wellbeing

Managers set the tone. Train them on the WTR basics, rest rules, how to handle opt-outs, and how to spot fatigue. Encourage employees to report when hours are pushing the limit and act quickly to adjust rotas. Simple controls-like a cap on consecutive long shifts-make a big difference.

Essential Contracts And Policies To Put In Place

Setting clear expectations in writing helps you stay compliant and avoid disputes as your team scales.

• Employment Contract: Define working hours, overtime, breaks, shift patterns, night work rules, opt-out arrangements (if used), and how hours are recorded and authorised. A well-drafted Employment Contract is your foundation.
• Staff Handbook: Include working time, breaks, fatigue management, authorising overtime/TOIL, and rota management. Your Staff Handbook is the practical playbook managers will use day-to-day.
• Working Time Policy And Opt-Out Form: Keep them separate so opt-outs are genuinely voluntary and easy to manage, and ensure you explain withdrawal rights.
• Night Work Policy (if applicable): Cover assessments, limits and additional safeguards.
• Overtime Policy: Align it with your contractual terms and confirm that overtime must be pre-authorised.

It can be overwhelming to know exactly which documents you need for your setup. Don’t stress-get the essentials right and build from there as your roster stabilises and your operating model matures.

Key Takeaways

• Working 70 hours a week in the UK isn’t automatically unlawful, but you must respect the 48-hour average weekly limit unless a worker voluntarily opts out, and you must still meet all rest, break and night work rules.
• There’s no single universal daily maximum, but daily rest (11 hours), weekly rest (24 hours per week or 48 per fortnight) and break requirements effectively limit legal shift length.
• Opt-outs must be voluntary, in writing, and can be withdrawn with notice; they don’t remove your duties around rest, safety and night work.
• Use clear, tailored documents-an Employment Contract and Staff Handbook-to set expectations on hours, breaks, overtime and record-keeping.
• Keep accurate time records for at least two years to demonstrate compliance with the Working Time Regulations, and monitor fatigue risks as part of your health and safety duties.
• Pay practices must comply with minimum wage rules and lawful wage deductions; premium overtime rates are a contractual choice, not a legal default.
• Night workers and young workers have stricter limits. Review your schedules against the rules on night work and breaks to avoid breaches.

If you’d like tailored help setting up contracts, opt-outs and compliant shift policies, you can reach us at 08081347754 or team@sprintlaw.co.uk for a free, no-obligations chat.