Working Time Regulations

The Working Time Regulations 1998 limit the average working week to 48 hours over a 17-week reference period. Workers can voluntarily opt out in writing. Night workers must not exceed 8 hours per 24-hour period on average and are entitled to free health assessments.

Last updated: February 2025

48 per week

Maximum average hours

17 weeks

Reference period

7 days minimum

Opt-out notice

What the Law Says

The Working Time Regulations 1998 implement the EU Working Time Directive (retained in UK law). Regulation 4 sets the 48-hour maximum averaged over 17 weeks. Regulation 5 limits opt-outs to voluntary written agreements that can be terminated with 7 days notice (or up to 3 months if agreed). Young workers (under 18) cannot opt out and are limited to 40 hours per week.

Your Obligations as an Employer

  • Ensure average working time does not exceed 48 hours unless opted out
  • Keep records of working hours for 2 years
  • Provide free health assessments to night workers
  • Ensure opt-outs are genuinely voluntary with no detriment for refusing

What to Include in Contracts

Include a working hours clause specifying normal hours, reference to WTR rights, an opt-out agreement as a separate document (not buried in the contract), and confirmation that opting out is voluntary and revocable.

View related contract template

Common Mistakes

  • Including the opt-out within the main employment contract rather than as a separate agreement
  • Pressuring employees to sign opt-outs as a condition of employment
  • Not monitoring actual hours worked even when opt-outs are signed

FAQ

Which workers are exempt from the 48-hour limit?

Certain workers are exempt including those with autonomous decision-making power over their working time, armed forces and emergency services in specific circumstances, domestic servants in private households, and workers in sea transport and inland waterways (covered by separate regulations).

Can an employer force overtime that breaches the 48-hour limit?

No, unless the employee has signed a valid opt-out. Even with an opt-out, the employer must ensure working hours do not endanger health and safety. An employer who forces excessive overtime may also breach the implied term of mutual trust and confidence.

Related Topics

Rest Break Requirements

Overtime Rules UK

Right to Disconnect

Stay compliant with UK employment law

AccountsOS generates compliant contracts and keeps you updated on your obligations. From £10/month.

Get Started Free

This is guidance for UK employers, not legal advice. For complex employment law matters, consult a qualified employment solicitor or ACAS.

View all employment law topics