Is unpaid overtime legal in the UK?

You stayed late all week. If the pay is short, your first move is simple: save the payslip and rota today, then write down every hour you worked. UK law sets no automatic overtime premium. Your contract sets any extra rate. But unpaid hours are not a free pass. They count when checking minimum wage and working time, and overtime pay you regularly receive can raise your holiday pay.

First, read the overtime clause

GOV.UK is explicit. Employers do not have to pay workers for overtime, though average pay for all hours worked must not fall below the National Minimum Wage. There is no statutory 1.5× or 2× rate for evenings, weekends or bank holidays. A contract may promise either, pay the usual hourly rate, offer time off in lieu (TOIL), or provide no extra payment. We think this is a bad deal for workers: employers benefit from a system that leaves any premium to the contract. That does not excuse paying below the minimum wage. If it promises a rate, the employer must honour it.

In care, record travel between visits as well as hands-on time; in a warehouse, hotel kitchen or shop, keep the rota and the actual finish time. A manager’s schedule is not proof you left when it says you did. If the contract promises an overtime rate, the employer must pay it.

TOIL is an agreement, not a statutory formula. One hour worked might earn one hour off, or more, depending on the terms. Working the hour still matters for minimum-wage and working-time checks; paid holiday is a separate entitlement.

Can I refuse overtime in the UK?

You only have to work overtime if your contract says so. If overtime is not guaranteed, the employer can generally stop offering it, but must not discriminate in who gets the opportunity. Refusing hours your contract requires can lead to a dispute or discipline; refusing genuinely voluntary hours is different. Read the actual clause, especially any notice or rota terms.

The usual working-time limit is an average of 48 hours a week over 17 weeks, including overtime. It is not a ban on every individual week above 48. Eight 55-hour weeks followed by nine 40-hour weeks average about 47.1 hours. Some jobs have exceptions, including certain emergency, security, seafaring and genuinely autonomous roles.

An adult can voluntarily opt out of the 48-hour average in writing. The agreement must be signed; an employer cannot dismiss or treat someone unfairly for refusing. You can withdraw it on at least seven days’ notice, or up to three months if the agreement says so. Some transport and maritime workers cannot opt out. Workers under 18 have a separate limit of eight hours a day and 40 a week and cannot opt out.

Check the minimum wage for every hour

The minimum wage is not a separate premium for each overtime hour. Check qualifying pay against hours counted in the relevant pay reference period. The calculation depends on whether the work is salaried-hours, time or another category. From 1 April 2026, the hourly minimum is £12.71 for those aged 21 and over, £10.85 for ages 18-20 and £8 for those under 18. The £8 apprentice rate applies to apprentices under 19, or aged 19 and over in their first apprenticeship year. After that, the age rate applies.

Salary is no exemption. Suppose a £30,000 salary covers 37.5 hours a week. As a rough comparison, £30,000 ÷ (52 × 37.5) is £15.38 per contractual hour. Work 50 hours every week for that £30,000 and the illustrative rate falls to about £11.54 per worked hour. For a real claim, use the actual pay periods and the salaried-hours rules, not a rough annual division. You must account for the additional hours.

Calculate contractual overtime pay

Overtime pay = overtime hours × the rate your agreement specifies.

Say your basic rate is £12.71 and the contract pays time-and-a-half above 40 hours. Five extra hours are paid at an exact overtime rate of £19.065. That gives 5 × £19.065 = £95.325, or £95.33 if the total is rounded half-up to the nearest penny. Basic pay is 40 × £12.71 = £508.40, so gross pay on that method is £603.73. If payroll rounds each overtime hour first to £19.07, it will calculate £95.35 instead. Check the rounding method on your payslip. Neither multiplier nor rounding convention comes from a statutory overtime rate.

On a salary of £30,000 with 37.5 contractual hours a week, a simple 52-week conversion gives £15.3846 per basic hour. If the agreement pays 1.25× for four extra hours, the unrounded calculation is 4 × (£30,000 ÷ 52 ÷ 37.5 × 1.25) = £76.92 to the nearest penny. Contracts with annualised hours or another divisor need their own calculation. Keep timesheets and payslips so you can compare the promise with what was paid.

When do part-time hours earn a premium?

Part-time workers have the same minimum-wage and working-time protection. The less-favourable-treatment rule does not generally require a premium just because someone exceeds their own part-time hours. The normal full-time threshold usually matters, unless their contract offers better terms. If full-time colleagues get enhanced rates for Sunday work or after 39 hours, compare like with like.

Take a 20-hour contract paying £13 an hour, with full-time hours of 39 and a 1.5× rate above 39. At 30 hours the worker gets 30 × £13 = £390, not a premium for hours 21-30. At 42 hours: 39 × £13 + 3 × £19.50 = £565.50. A different contract could pay the premium sooner.

Does overtime increase holiday pay?

Yes, where overtime payments are part of normal pay. Acas says regularly received overtime pay belongs in at least four weeks of holiday pay for most workers. An employer can apply it to the full 5.6 weeks; for irregular-hours and part-year workers, relevant payments must be included across all 5.6 weeks. Guaranteed and non-guaranteed overtime payments count; voluntary overtime counts when paid regularly. An occasional extra shift does not automatically set a new normal.

For fixed hours but variable pay, Acas uses the average hourly rate over the previous 52 weeks, excluding holiday pay from the reference calculation. For irregular-hours and part-year workers the method differs, including how holiday pay is treated. Unpaid or low-paid weeks may require looking further back, up to 104 weeks. Check your working pattern before averaging.

Do not assume every pay scheme treats overtime alike. Northern Ireland guidance says guaranteed contractual overtime is counted for statutory maternity, paternity and adoption pay, while non-guaranteed overtime usually is not. For a family-pay claim, check the particular statutory calculation and earnings period.

Agency, casual and self-employed work

Agency workers have worker protections from day one. After 12 weeks in the same role with the same hirer, equal treatment on pay includes a comparable direct recruit’s overtime premium. The clock can pause during certain short breaks, sickness or annual leave, and can reset after a break of more than six weeks or a substantively different role. If the hirer’s employees get time-and-a-half after 40 hours, ask the agency which equivalent rate it uses once you qualify.

Zero-hours and casual workers are not exempt from the minimum wage or working-time rules. But the absence of guaranteed hours does not itself create a premium. The agreement still determines any overtime rate. If someone called “self-employed” is in fact a worker, their real status, rather than the label, determines protection.

Does the answer change across the UK?

The core overtime position is the same in England, Wales and Scotland: no statutory premium, a minimum-wage floor and working-time limits for covered workers. Northern Ireland has separate employment legislation but nidirect gives the same no-premium answer; its working-time rules also use a 48-hour average, normally over 17 weeks. National Minimum Wage rates apply across the UK.

Some procedures differ. Nidirect says written employment terms in Northern Ireland must be supplied within two months of starting, rather than Great Britain’s day-one rule, and points readers to the Labour Relations Agency instead of Acas. The Employment Rights Act 2025 tribunal-time-limit reform discussed below is a Great Britain change. Do not assume it extends a Northern Ireland deadline. For breach-of-contract claims in Scotland, the new limit starts on 9 November 2026, not 1 October.

What to do if the figures do not add up

1. Write down the hours. Keep rotas, messages and payslips. Check what the contract promises and the total hours worked in each pay period.
2. Calculate both claims. Separate unpaid contractual overtime from a minimum-wage shortfall. Either, both or neither may apply.
3. Raise it promptly. Ask payroll for the calculation and missing pay in writing. Speak to your union: Unite covers many hospitality, retail and logistics workers; UNISON represents many care and health workers; GMB also organises across care and delivery. Citizens Advice, a law centre or Acas can help; in Northern Ireland contact the Labour Relations Agency. Report suspected minimum-wage underpayment through HMRC’s minimum wage complaint route. If agency recruitment involves labour exploitation, contact the GLAA; report dangerous fatigue risks to HSE and discrimination in overtime allocation to the EHRC.
4. Watch the deadline. In Great Britain, for most tribunal claims whose time limit starts on or after 1 October 2026, the ordinary period is six months minus one day. Earlier-starting limits may still be three months minus one day; Scotland contract claims switch on 9 November. Notify Acas in time for early conciliation. Timely notification pauses the limit.

The Fair Work Agency was established on 7 April 2026. It has statutory responsibility for minimum-wage enforcement, but HMRC carries out that work under contract during its first year, before the planned transfer from April 2027. Do not wait for an agency reorganisation before reporting an underpayment or protecting a tribunal deadline.

What has changed, and what is still planned?

The Employment Rights Act 2025 has not created a statutory overtime premium. The developments that matter are claim deadlines and, later, predictable hours for people who repeatedly work more than their contracted hours.

1. 1 Apr 2026Minimum-wage rise. In force

   The 21+ rate became £12.71 an hour; the younger and apprentice rates changed too.

2. 7 Apr 2026Fair Work Agency. Established

   HMRC continues to deliver minimum-wage enforcement under contract in the first year.

3. 1 Oct 2026Tribunal limit. In force in Great Britain

   Most claims with a time limit starting from this date have six months minus one day; Scottish contract claims follow on 9 November.

4. 1 Jan 2027Dismissal changes. Scheduled

   For dismissals from this date, the ordinary unfair-dismissal qualifying period is scheduled to fall to six months; fire-and-rehire protections are also due.

5. 2027Guaranteed hours. Planned

   Rights to guaranteed hours for qualifying zero- and low-hours workers, reasonable notice of shifts and short-notice payments are planned; the government says timing and detail depend on consultation.