Guide
Working time: legal limits and rest breaks
Legal requirements for maximum working hours, rest breaks, and annual leave. Covers the 48-hour weekly limit, opt-out agreements, rest entitlements, night worker protections, and holiday pay calculations for employers.
The Working Time Regulations 1998 protect workers from excessive working hours and ensure they receive adequate rest. As an employer, you must comply with these rules for all workers and employees, including agency workers and most freelancers.
Breaking these rules can result in enforcement action from the Health and Safety Executive, employment tribunal claims, and criminal prosecution in serious cases.
Understanding the 48-hour limit
The 48-hour limit is an average calculated over a reference period, not a weekly cap. This gives you flexibility to manage busy periods as long as the average stays within limits.
How averaging works
The standard reference period is 17 weeks. Add up all working hours over this period and divide by 17. The result must not exceed 48 hours.
Example: A worker does 55 hours in week 1, 45 hours in week 2, and 40 hours for the remaining 15 weeks. Total: 55 + 45 + (40 × 15) = 700 hours. Average: 700 ÷ 17 = 41.2 hours per week. This is within the limit.
What counts as working time
- Time spent doing your job, including overtime (paid or unpaid)
- Job-related training
- Time spent travelling as part of the job (but not ordinary commuting)
- Working lunches or business meals
- Time on call at the workplace
What does not count
- Breaks when no work is done
- Travel between home and a fixed workplace
- Time on call if you can sleep or do your own activities
- Paid holidays (these are rest, not work)
Opting out of the 48-hour limit
Workers aged 18 or over can choose to work more than 48 hours per week by signing a voluntary opt-out agreement. This is entirely the worker's choice.
Rules for opt-out agreements
- Must be in writing
- Must be genuinely voluntary - you cannot require it as a condition of employment
- Can cover a specific period or be open-ended
- Worker can cancel with at least 7 days' notice (or longer if agreed, up to 3 months maximum)
What you cannot do
- Dismiss someone or treat them unfairly for refusing to opt out
- Refuse to hire someone because they will not sign an opt-out
- Put pressure on workers to sign opt-outs
Even when a worker has opted out, you still have a duty of care for their health and safety. You should monitor working hours and watch for signs of fatigue or stress.
Young workers cannot opt out
Workers under 18 cannot opt out. The limits of 8 hours per day and 40 hours per week are absolute, not averages.
Rest breaks: practical application
The regulations set minimum rest periods. Your contracts can be more generous but cannot provide less.
During the working day
If a worker works more than 6 hours, they are entitled to an uninterrupted break of at least 20 minutes. This break:
- Must be taken during the shift, not at the start or end
- Should allow the worker to rest away from their workstation
- Does not have to be paid (unless your contract says otherwise)
Practical tip: Many employers provide a 30-minute or 1-hour break, but only 20 minutes is legally required.
Between working days
Workers must have at least 11 consecutive hours' rest between finishing work one day and starting the next.
Example: A worker who finishes at 11pm cannot start before 10am the next day.
Weekly rest
Workers can choose between:
- 24 hours uninterrupted rest in each 7-day period, or
- 48 hours uninterrupted rest in each 14-day period
This is in addition to the 11-hour daily rest. So a worker who finishes on Saturday evening might not be required to work again until Monday morning.
Night worker protections
Night workers have additional protections because night work can affect health more than day work.
Who is a night worker?
You are a night worker if you regularly work at least 3 hours during the night period (11pm to 6am, unless varied by agreement). "Regularly" is not defined in law but generally means as a normal course of employment, not occasionally.
Working time limits for night workers
Night workers must not work more than an average of 8 hours in any 24-hour period. Unlike the 48-hour week, this average is calculated over 17 weeks by default.
Special hazardous work: If the work involves special hazards or heavy physical or mental strain, the 8-hour limit applies to every 24-hour period, not as an average.
Health assessments
You must offer night workers a free health assessment before they start night work and regularly thereafter (typically annually). You cannot require workers to have an assessment, but you must offer it.
If a health professional advises that a worker should not do night work, you should try to transfer them to suitable day work if available.
Young workers (under 18)
Workers under 18 have enhanced protections that cannot be waived or opted out of.
Working time limits
- Maximum 8 hours per day (not an average - a firm limit)
- Maximum 40 hours per week (not an average - a firm limit)
- Cannot work between 10pm and 6am (or 11pm to 7am) in most cases
Rest breaks
- 30 minutes if working more than 4.5 hours (compared to 20 minutes for adults)
- 12 hours' rest between working days (compared to 11 hours for adults)
- 48 hours' weekly rest (compared to 24 hours for adults)
Exceptions
Some exceptions apply in specific industries where young workers must work to maintain continuity of service, but compensatory rest must be provided.
Annual leave entitlement
The Working Time Regulations also set minimum paid annual leave entitlements. This applies to all workers, not just employees.
Calculating holiday pay
Holiday pay must reflect what the worker would have earned if they had been at work. The calculation depends on whether the worker has regular or irregular hours.
Workers with regular hours
If a worker works fixed hours each week, calculate holiday pay based on their normal weekly pay including:
- Basic salary
- Regular contractual overtime
- Regular commission and bonuses
- Regular allowances (but not expense reimbursements)
Workers with irregular hours or part-year workers
For workers whose hours vary, use the rolled-up accrual method from April 2024:
- Calculate 12.07% of hours worked in each pay period
- Add this to their pay in each period
- Clearly show the holiday pay element on payslips
Example: A worker earns £15 per hour and works 20 hours in a week. Holiday pay for that week = 20 × £15 × 12.07% = £36.21.
Reference period for variable pay
For workers with variable earnings (commission, performance bonuses), calculate average pay over the previous 52 weeks worked. Exclude any weeks with no pay.
The two-pot system
Since April 2024, the law treats the first 4 weeks of leave differently from the additional 1.6 weeks:
- First 4 weeks: Must reflect normal earnings including overtime, commission, and bonuses
- Additional 1.6 weeks: Can be paid at basic rate only (no commission or overtime)
Record keeping
You must keep adequate records to show you are complying with the Working Time Regulations. There is no prescribed format, but records should demonstrate:
- Workers are not exceeding the 48-hour average (or have opted out)
- Night workers are not exceeding the 8-hour average
- Workers are receiving their rest breaks and periods
- Young workers are within their strict limits
Keep records for at least 2 years. The Health and Safety Executive can request to see these records.
Exemptions and special cases
Some workers are wholly or partly exempt from the Working Time Regulations:
Fully exempt
- Genuinely self-employed people (not workers)
- Managing executives with autonomous decision-making powers
- Family workers in a family business
Modified rules apply
- Mobile transport workers (road, rail, air, sea) - separate regulations
- Armed forces, police, emergency services during emergencies
- Workers in roles requiring 24-hour staffing with compensatory rest
- Domestic servants in private households
If in doubt about whether exemptions apply, seek legal advice. Getting it wrong can result in tribunal claims.