Working Time Regulations for Employers

The Regulations impose a maximum average working week of 48 hours, calculated over a reference period of 17 weeks (or up to 52 weeks by collective agreement). The calculation includes all time the worker is at work — regular hours, overtime, time on-call at the workplace, and mandatory training. Travel to and from work does not count.

Adult workers (not young workers under 18) may voluntarily sign a written opt-out agreement agreeing to work more than 48 hours per week. The opt-out is personal — it cannot be a condition of employment, and a worker can cancel it at any time by giving written notice (the default cancellation period is seven days, though a longer notice period of up to three months can be agreed in writing). Never pressurise workers to opt out — doing so undermines the legal validity of the opt-out and could constitute unlawful detriment.

Workers are entitled to the following minimum rest:

• In-work rest break: a 20-minute uninterrupted break if the working day exceeds six hours. The break does not have to be paid (unless the contract provides for paid breaks) but must be taken away from the workstation
• Daily rest: at least 11 consecutive hours between working days
• Weekly rest: at least 24 consecutive hours without work in each seven-day period (or 48 hours in each 14-day period)

Young workers (under 18) have more generous entitlements: a 30-minute break for working days over 4.5 hours, 12 hours daily rest, and 48 hours weekly rest. Special rules apply to certain sectors — road transport, seafarers, domestic workers in private households, and some others are excluded from or have modified Regulations. Shift workers and those with unmeasured working time have some modifications too.

Almost all workers are entitled to 5.6 weeks of paid annual leave per year — this equates to 28 days for a full-time five-day-a-week worker (including any bank holidays). Part-time workers receive a pro-rata entitlement. The statutory entitlement cannot be replaced by a payment in lieu, except upon termination of employment.

From April 2024, the rules for calculating holiday pay for irregular-hours workers and part-year workers changed — holiday entitlement for these workers is now calculated as 12.07% of hours worked in each pay period (the accrual method), replacing the previous 12-week averaging method. Employers must not attach conditions to holiday pay that reduce it below what the worker is contractually owed — for example, including only basic pay when regular overtime is a normal part of the job may be unlawful following the Supreme Court's ruling in Flowers v East of England Ambulance Trust.

The Working Time Regulations 1998 are enforced primarily by the Health and Safety Executive (HSE) (for most sectors) and by local authority environmental health teams (for some retail and hospitality environments). Enforcement is complaint-driven as well as proactive, and the HSE can issue improvement notices requiring employers to comply within a specified period. Criminal prosecution for persistent breach is possible. Workers can also bring Employment Tribunal claims for failure to allow rest breaks or annual leave entitlement.

Employers must keep records to demonstrate compliance with the 48-hour average and the night work limits. The records need to be kept for at least two years. Following the 2019 ECJ ruling in CCOO v Deutsche Bank SAE, which held that EU member states must require employers to have an objective, reliable system for measuring daily working time, there is some pressure on the UK to clarify its position post-Brexit. While the UK is no longer bound by EU law, HMRC and HSE guidance increasingly recommends systematic time records — and Employment Tribunals are sceptical of employers who claim to have no record of hours worked when a worker alleges a breach.

Holiday pay calculations remain a fertile source of Employment Tribunal claims. The leading cases — Bear Scotland v Fulton, Harpur Trust v Brazel, and the Supreme Court's decision in Flowers v East of England Ambulance Trust — established that holiday pay must reflect normal pay, including regular overtime, commission, and some allowances. Employers who pay only basic salary in respect of statutory holiday leave may be exposed to back-claims. From April 2024, the Retained EU Law (Revocation and Reform) Act 2023 changes also simplified the holiday pay rules for irregular-hours workers, replacing the 52-week reference period method with the 12.07% accrual method — reducing the administrative burden while maintaining entitlement levels.