Managing leave for part-time staff in the United Kingdom
Reviewed by Mellow Editorial Team, HR & payroll content team
Part-time workers in the UK have exactly the same statutory leave entitlement as full-time workers, calculated on a pro-rata basis. The key principle is straightforward: a part-time employee should never receive less generous leave terms than a comparable full-time employee, simply because they work fewer hours or days.
The statutory minimum and how pro-rata works
Full-time employees working five days a week are entitled to 5.6 weeks of annual leave, which equals 28 days including bank holidays. Part-time staff get the same 5.6 weeks, but the number of days reflects how many days a week they work.
A simple formula applies:
Days worked per week × 5.6 = annual leave entitlement in days
Some examples:
- 3 days per week: 3 × 5.6 = 16.8 days
- 4 days per week: 4 × 5.6 = 22.4 days
- 2.5 days per week: 2.5 × 5.6 = 14 days
You can round up fractions but you are not required to round down. Rounding down would give the employee less than their legal entitlement, which puts you at risk of an unlawful deduction from wages claim.
For workers with irregular hours or compressed schedules, it is often cleaner to calculate entitlement in hours rather than days. Multiply the average weekly hours by 5.6 to get the annual entitlement in hours.
Bank holidays and part-time workers
This is where many employers get it wrong. Bank holidays do not automatically form part of a part-time worker's entitlement just because they fall on a day that worker would otherwise be off. However, a part-time worker is also not entitled to the same number of bank holiday days as a full-time colleague purely by default.
What matters is how your contracts are written. If you state that employees get "28 days inclusive of bank holidays", that 28-day pot is distributed equally in proportion to hours worked. A worker doing three days a week gets 16.8 days in total — they can use that allowance on bank holidays that fall on their working days, but they are not guaranteed every bank holiday off.
The problem arises when most bank holidays fall on Mondays. A worker whose rest day is Monday could miss out on bank holiday benefit disproportionately compared to full-time colleagues. This is not automatic discrimination, but it is worth addressing clearly in your contracts and leave policy to avoid disputes. Many employers address it by calculating leave purely in hours and letting staff use their allocation flexibly.
Accrual during the first year and on leaving
During the first year of employment, leave accrues as it is taken rather than being granted in full upfront — unless your contract says otherwise. For a part-time employee who joins mid-year, the pro-rata calculation still applies: take the annual entitlement, divide it by 52, and multiply by the number of weeks remaining in the leave year.
When an employee leaves, any accrued but unused leave must be paid out. The payment should reflect normal remuneration, not just basic pay — HMRC guidance and case law make clear that regular overtime and certain allowances should be reflected in holiday pay calculations. For part-time staff on variable hours, use an average of their earnings over a reference period (currently 52 weeks of actual pay, excluding unpaid weeks) to arrive at a week's pay.
Sickness and leave accrual for part-time workers
Part-time employees continue to accrue statutory annual leave while absent on sick leave, including periods covered by Statutory Sick Pay. If a worker is long-term sick and has been unable to take their leave during the leave year, they have the right to carry it over. The statutory minimum leave (4 weeks under the Working Time Regulations) can be carried into the next leave year in these circumstances; any contractual leave above that is subject to your own policy.
The Employment Rights Act 2025 has strengthened day-one rights across several areas, and it is worth reviewing your contracts to ensure they reflect the current baseline — particularly around flexible working requests, which part-time staff are more likely to make.
Record-keeping and practical management
Accurate records are essential. Your payroll or HR system should track entitlement, bookings and remaining balance in the same unit — ideally hours for anyone on non-standard patterns — so that part-time staff and their managers can see at a glance what is available.
When managing payroll across multiple employment types, consistency in how leave is recorded and paid reduces errors and prevents small miscalculations from becoming formal grievances. Build the pro-rata calculation into your contract template, state clearly whether bank holidays are included or additional, and set out the reference period used for holiday pay. Those three steps resolve the majority of disputes before they start.
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