The Working Time Regulations 1998 set the basic limits on working hours in Great Britain. A worker cannot be required to work more than an average of 48 hours a week, normally averaged over 17 weeks, unless they agree in writing to opt out. Workers are also entitled to 11 hours' rest between working days, 24 hours off each week, a 20-minute break when they work more than six hours, and 5.6 weeks of paid annual leave. Since 6 April 2026 employers must also keep holiday records for six years.
Who the regulations cover
The regulations protect "workers", which is wider than employees. Agency workers are covered by regulation 36 even where they have no worker's contract. People in business on their own account, whose engagers are their clients or customers, are not covered. Some rights differ for young workers: those who are over compulsory school age but under 18. Some limits also do not apply where working time is not measured or predetermined, or can be set by the worker themselves. The regulations give managing executives or others with autonomous decision-taking powers, family workers and workers officiating at religious ceremonies as examples.
The 48-hour week and the opt-out
Regulation 4 limits working time, including overtime, to an average of 48 hours for each seven days over the reference period. The reference period is any 17 weeks, or successive 17-week periods if a relevant agreement says so. A collective or workforce agreement can extend it to up to 52 weeks for objective or technical reasons, or for reasons concerning the organisation of work. Days of annual leave, sick leave and family leave are "excluded days". Hours worked immediately after the reference period are added to replace them, so time off does not dilute the average.
An adult worker can agree in writing to work more. The opt-out:
- Must be voluntary. Section 45A of the Employment Rights Act 1996 protects a worker from detriment for refusing to sign one;
- Can be ended by the worker. They give at least seven days' written notice, or a longer period set in the agreement, which cannot exceed three months;
- Must be recorded. The employer must keep up-to-date records of the workers who have opted out.
Young workers cannot opt out. Their working time is limited to eight hours a day and 40 hours a week, with no averaging.
Worked example
A warehouse supervisor works 55 hours a week for 12 weeks during a peak season and 30 hours a week for the next five. Over the 17 weeks that is (12 × 55) + (5 × 30) = 810 hours, an average of 47.6 hours a week. That is within the limit without an opt-out. If the peak ran for 14 weeks instead, the average would be 50.6 hours, and the employer would need a signed opt-out or a change to the rota.
Rest periods and breaks
| Right | Adult workers | Young workers (under 18) |
|---|---|---|
| Daily rest (reg 10) | 11 consecutive hours in each 24 hours | 12 consecutive hours |
| Weekly rest (reg 11) | 24 hours uninterrupted each 7 days, or 48 hours (or two 24-hour periods) each 14 days | 48 hours each 7 days, which can be reduced to no less than 36 hours for technical or organisational reasons |
| Rest break (reg 12) | 20 minutes uninterrupted if the working day is more than 6 hours | 30 minutes if the working day is more than 4.5 hours |
The statutory break does not have to be paid unless the contract says so. The worker is entitled to spend it away from their workstation. Collective or workforce agreements can vary the details for adult workers.
Night workers
Unless an agreement says otherwise, night time is 11pm to 6am. A night worker is someone who normally works at least three hours of their daily working time during night time. Their normal hours must not exceed an average of eight hours in each 24, averaged over 17 weeks. Before assigning someone to night work, the employer must offer a free health assessment.
Annual leave
The statutory entitlement is four weeks under regulation 13 plus 1.6 weeks under regulation 13A, which is 5.6 weeks in total, capped at 28 days. A worker on a five-day week therefore gets 28 days, and bank holidays can count towards it. Leave cannot be replaced by a payment in lieu except when employment ends, and leavers are paid for leave accrued but not taken. Leave that could not be taken because of sickness can be carried forward, but must be taken within 18 months of the end of the leave year in which it arose. For leave years starting on or after 1 April 2024, irregular hours and part-year workers accrue leave at 12.07% of the hours they work in each pay period. Our guides to holiday pay and pro rata entitlements explain the calculations.
Record keeping
Employers must keep records that are adequate to show compliance with the weekly, night work and young worker limits, and retain them for two years. Since 1 January 2024 they do not have to record each worker's daily hours if they can show compliance some other way.
The Employment Rights Act 2025 added a separate duty, in force from 6 April 2026. Employers must keep records adequate to show they have complied with annual leave entitlement and holiday pay, including payments in lieu on termination, and retain them for six years. Failure to keep these records is a criminal offence. For most employers the practical answer is to make sure payroll and HR systems keep leave balances, leave taken and the pay rate used for each period of leave, and do not delete them after two years.
Sources: Working Time Regulations 1998; Employment Rights Act 2025, section 35; Employment Rights Act 1996, section 45A; GOV.UK: maximum weekly working hours.
Acumon's payroll management service keeps the holiday and pay records the 2026 rules require, and our payroll audit team can test existing records for gaps.