Working Time Regulations

Under the Working Time Regulations 1998, your employer cannot require you to work more than an average of 48 hours per week unless you have signed a valid individual opt-out agreement. The 48 hours is an average calculated over a 17-week reference period — so some weeks can be longer and some shorter, provided the average does not exceed 48 hours.

Working time includes all time you are at the employer's disposal and carrying out your activities or duties. It does not include rest breaks or time spent on call at home (in most cases). Travelling to and from work is generally not working time, except for workers with no fixed place of work (such as mobile workers) for whom travel from their home to a client may count.

Your employer must take all reasonable steps to ensure the average does not exceed 48 hours. They cannot simply ignore the limit — if they are aware you are routinely exceeding it, they must act.

Workers can voluntarily agree to work more than 48 hours per week by signing an individual written opt-out agreement. Key rules:

• The opt-out must be voluntary — you cannot be forced to sign one as a condition of employment or offered inducements to sign.
• It must be in writing and signed by you personally.
• You can cancel the opt-out at any time by giving your employer at least seven days' notice (or up to three months if your opt-out specifies a longer cancellation period).
• Your employer cannot dismiss or penalise you for refusing to sign an opt-out, or for cancelling one you have already signed.

Even with an opt-out in place, you are still protected by the minimum rest break entitlements and daily and weekly rest requirements — these cannot be opted out of. Young workers (aged 16–17) cannot opt out of the 48-hour limit at all.

Employers are required to keep adequate records to show compliance with the 48-hour average limit (and to be able to demonstrate that opted-out workers are not being forced to work excessive hours in a way that endangers their health and safety). Since a Court of Justice ruling, the obligation to keep records is significant.

If you believe you are being required to work more than 48 hours a week without an opt-out, or that your rest entitlements are not being met, you can:

• Raise the matter informally or through a written grievance with your employer
• Report a concern to the Health and Safety Executive (for health and safety aspects) or the Employment Tribunal (for contractual enforcement)
• Bring a claim in the Employment Tribunal for breach of the Working Time Regulations

Time limits for Employment Tribunal claims under the Working Time Regulations are three months less one day from the date of the breach.

The Workers (Predictable Terms and Conditions) Act 2023 — which received Royal Assent in September 2023 but was awaiting implementation regulations when this guide was updated — will give workers and agency workers the right to request a more predictable working pattern where their existing pattern is uncertain. This is particularly relevant for those on zero-hours or variable-hours contracts who regularly work hours near or above the 48-hour weekly threshold.

Under the Act, a worker with at least 26 weeks of service will be able to make up to two applications per year to their employer requesting a more predictable work pattern in terms of hours, days worked, or the duration of the contract. Employers must consider requests in a reasonable manner and may only refuse on specific statutory grounds — broadly, the business grounds set out in the Act.

While the Act does not alter the 48-hour weekly maximum directly, it interacts with it in practice: a worker who can establish a more predictable pattern through a successful request will find it easier to track and challenge working time breaches, and employers will have clearer visibility over their exposure under the Working Time Regulations.

Key points to watch as the Act is implemented:

• The right to request applies to workers as well as employees — a broader category than many working time rights
• Agency workers will have a modified right to apply to their agency or the end-user hirer
• Detriment for making a request or for exercising rights under the Act will be unlawful
• The Acas Code of Practice on this right will be published alongside the implementation regulations — monitor the Acas website for updates

Separately, the Employment Rights Bill 2024 proposed to ban zero-hours contracts as a standard form of engagement and to require employers to offer guaranteed hours to workers on zero or variable hours contracts where the pattern of hours worked reflects a stable and regular arrangement. This would significantly reduce the problem of workers routinely exceeding the 48-hour limit due to variable or excessive informal hour-working. The Bill also proposed strengthening protections for workers who are penalised for refusing to accept unpredictable hours. Monitor Parliament's progress on these provisions at legislation.gov.uk.

For workers who have signed an opt-out from the 48-hour average but are concerned about the health effects of long working hours, the most practical route is to cancel the opt-out by giving the requisite written notice, and then to raise a grievance if the employer attempts to penalise the cancellation. The Health and Safety Executive (HSE) also provides guidance on managing fatigue at work, which may be relevant where occupational health concerns arise from excessive hours. Workers in safety-critical industries — including transport, healthcare, and construction — should be particularly aware that employer responsibilities under the Health and Safety at Work Act 1974 sit alongside the WTR, and that fatigue caused by excessive hours can constitute a health and safety breach independent of the working time limits.