Legal guide
UK overtime law guide
This page holds the deeper legal context for the UK overtime calculator: contractual overtime pay, the 48-hour weekly limit, voluntary and compulsory overtime, minimum wage checks, holiday pay, and ACAS dispute steps.
Use the UK overtime calculatorIs overtime pay legally required in the UK?
Usually no. UK law does not create a universal right to a higher overtime rate. Your employment contract, staff handbook, rota policy, or collective agreement usually decides whether extra hours are paid at normal time, time and a half, double time, time off in lieu, or another arrangement.
Contractual overtime: voluntary, guaranteed, and compulsory
Voluntary overtime
The employer can offer extra hours, but the worker is not normally required to accept them.
Guaranteed overtime
The employer is contractually required to offer overtime, and the worker is usually required to work it.
Non-guaranteed compulsory
The employer is not required to offer overtime, but the worker must work it when it is offered under the contract.
The 48-hour weekly limit
Most adult workers cannot be required to work more than 48 hours a week on average, usually averaged over a reference period. A worker can choose to opt out, but the opt-out must be voluntary and in writing. Workers must not be dismissed or treated unfairly for refusing to opt out.
The 48-hour rule is a working-time safety rule. It does not by itself create an overtime pay premium. Pay still comes from the contract or wage policy.
Minimum wage and working time checks
If extra hours are unpaid or paid at a low rate, the average hourly pay calculation matters. Mandatory deductions, unpaid required training, unpaid travel between work sites, or unpaid pre-shift work can push average pay below the legal wage floor.
- Count all hours the worker is required to work.
- Include required training, handover, and work-related travel where applicable.
- Compare total pay against the relevant minimum wage rate for the worker.
Overtime and UK holiday pay
Regular overtime can affect holiday pay where it forms part of normal remuneration. This is different from asking whether overtime itself must be paid at a premium. The practical question is whether overtime, shift premiums, or commission are normal enough to be reflected in paid leave.
If overtime is underpaid
Workers can raise the issue with payroll or HR first, then contact ACAS for guidance. Many employment disputes require ACAS Early Conciliation before an Employment Tribunal claim. Tribunal deadlines can be short, so workers should not wait if there is a live wage dispute.