Irregular-hours workers are entitled to 12.07% of hours worked as paid holiday (Working Time Regulations 1998, reg.15B; effective for leave years beginning on or after 1 April 2024). When that holiday is taken, pay must reflect average weekly earnings over a 52-week reference period under Working Time Regulations 1998, regulation 16. Only weeks in which the worker was actually paid count — weeks without work are excluded and earlier paid weeks substituted. Normal pay including regular overtime and commission must be included. These rules were reformed by the Working Time (Amendment) Regulations 2023. Updated June 2026.
Source: Working Time Regulations 1998, reg.13, reg.15B and reg.16 (as amended by Working Time (Amendment) Regulations 2023); acas.org.uk/irregular-hours-and-part-year-workers.
What the law says
The right to paid annual leave for all workers — including those on irregular-hours contracts — is set out in the Working Time Regulations 1998, regulation 13. The statutory minimum is 5.6 weeks per leave year.
How much holiday pay must be paid is governed by regulation 16, which requires holiday pay to reflect the worker's "normal remuneration." For irregular-hours workers, the Working Time (Amendment) Regulations 2023 introduced regulation 15B (effective for leave years starting on or after 1 April 2024), which specifies the 52-week reference period method. Source: gov.uk/holiday-entitlement-rights.
The 52-week reference period
How the reference period works
The 52-week reference period runs backwards from the day before the first day of holiday. You count back 52 weeks in which the worker received pay. Any week with no earnings is skipped — earlier paid weeks are substituted in its place. The result is always 52 paid weeks, however long it takes to reach them.
Example: A worker takes a week's holiday beginning 1 September 2026. The reference period runs back through the 52 most recent paid weeks before 31 August 2026. A week in January 2026 when the worker had no work is excluded; the calculation goes back to include a paid week in December 2025 instead.
Workers employed for fewer than 52 weeks
If the worker has been employed for fewer than 52 weeks, the reference period covers all the full weeks of employment in which they received pay. Source: WTR 1998, reg.16; acas.org.uk/irregular-hours-and-part-year-workers.
What counts as normal pay
Courts and tribunals have consistently held that holiday pay must include all payments that are intrinsically linked to the performance of the worker's contractual tasks. ACAS confirms this means:
Included in normal pay:
- Basic wages.
- Regular overtime — including compulsory overtime and voluntary overtime that is regular and settled in pattern.
- Commission that forms a normal part of the worker's remuneration.
- Shift premiums that are a routine feature of the role.
Not included in normal pay:
- Purely ad hoc voluntary overtime without any regular pattern.
- Expenses and reimbursements.
- Discretionary bonuses not linked to performance of specific tasks.
- Employer pension contributions.
The key test is regularity and intrinsic connection to work. A stream of overtime paid every week for three years is "regular" even if it is technically called "voluntary." Source: acas.org.uk/irregular-hours-and-part-year-workers.
Rolled-up holiday pay: the alternative method
From 1 April 2024, employers may use rolled-up holiday pay for irregular-hours and part-year workers as an alternative to the 52-week reference period method. Under rolled-up pay:
- The employer adds 12.07% to each pay packet during the leave year to cover holiday pay.
- The 12.07% element must be itemised separately on the payslip — it cannot be absorbed into a flat hourly rate.
- When the worker takes holiday, the leave is unpaid — they have already received the holiday pay as part of earlier payslips.
Rolled-up holiday pay may not be used for full-time or standard part-time employees. It can only lawfully be used where the worker qualifies as an irregular-hours or part-year worker under WTR 1998, reg.15B. Source: WTR 1998, reg.15F; acas.org.uk/irregular-hours-and-part-year-workers.
Your rights if holiday pay is underpaid
If your employer pays only basic pay during holiday and you regularly work overtime or earn commission, you may be underpaid. Your options:
- Raise a grievance with your employer, setting out the payments you believe should have been included in your holiday pay.
- Contact ACAS for free advice and, if required, to initiate early conciliation before any tribunal claim.
- Bring an employment tribunal claim for unlawful deduction from wages. The time limit is three months less one day from the date of the last underpayment (or the last in a series of connected deductions). Early conciliation notification to ACAS is required first.
Source: Employment Rights Act 1996, s.13; Employment Tribunals Act 1996, s.18A; acas.org.uk/irregular-hours-and-part-year-workers.
Calculate your holiday entitlement
Use the free annual leave calculator to work out your entitlement as an irregular-hours or zero-hours worker. The calculator uses the WTR 1998 reg.15B accrual method.
Frequently asked questions
See the FAQ below for sourced answers. For individual disputes about holiday pay, contact ACAS or call the ACAS helpline.
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