Guide
Part-time holiday entitlement: pro-rating that survives a tribunal
Updated
Pro-rating leave is one multiplication, yet it often goes wrong because the starting figure is wrong. Almost every error is a full-time figure with bank holidays baked in.
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- The statutory floor is 5.6 weeks' paid holiday a year. gov.uk states that "almost all people classed as workers are legally entitled to 5.6 weeks' paid holiday a year". It adds that "most workers who work a 5-day week must receive at least 28 days' paid annual leave a year" (gov.uk).
- The 28 day ceiling is applied to the regular hours figure. gov.uk states that "statutory paid holiday entitlement is limited to 28 days". So a six or seven day week does not produce more than 28 days of statutory leave (gov.uk).
- Part-time entitlement is days a week multiplied by 5.6, the calculation gov.uk and Acas both work. A three day week gives "at least 16.8 days' leave a year (3 x 5.6)" (Acas).
- Irregular hours and part-year workers accrue 12.07% of actual hours worked in a pay period, for leave years beginning on or after 1 April 2024. That percentage is 5.6 weeks divided by the 46.4 working weeks of a year (gov.uk).
- Bank holidays are treated as a setting, not a fact, because they are one. gov.uk: "bank or public holidays do not have to be given as paid leave". And "an employer can choose to include bank holidays as part of a worker's statutory annual leave" (gov.uk).
- The carry-over figure uses the general rule that "workers can normally carry over a maximum of 8 days into the next leave year, with the agreement of their employer". Statutory family leave is treated differently and is not modelled here (gov.uk).
- This tracks the statutory minimum for a full leave year. It does not model contractual leave above the floor, service-related uplifts, leave in the first year of a job under an employer's accrual scheme, or a leave year part-completed. Where the contract is more generous, the contract governs and this figure is the legal floor beneath it.
- Converting accrued hours to days uses the normal day length you enter. That conversion is a presentation choice, not a statutory rule: the entitlement of an irregular hours worker is measured in hours.
The calculation
Acas states the rule plainly: "someone who works part time is still entitled to 5.6 weeks' statutory paid holiday". And "the entitlement will be in proportion to the hours they work". Its worked example gives a three day week 16.8 days of paid holiday a year (3 x 5.6).
gov.uk gives the same example and the same arithmetic. Days worked in a normal week times 5.6, and nothing else enters the sum.
The error that survives audits
The common failure is to pro-rate 20 days rather than 28, because 20 was the number left after the employer's bank holidays were deducted from a full-time entitlement.
Pro-rating 20 days for a three day week gives 12 days. The statutory floor is 16.8. The gap is nearly five days a year, per worker, and it survives because the resulting number looks plausible.
The test is to pro-rate the statutory entitlement first, then deal with bank holidays. Doing it in the other order compounds a policy choice into a legal shortfall.
Weeks, not days, when the pattern is unusual
For a worker whose days vary in length, days are a poor unit. The entitlement is 5.6 weeks, and a week means a week of that worker's normal hours.
Where a pattern makes days-per-week meaningless, the safer route is to convert the entitlement to hours and track it in hours. The law already requires that for irregular hours workers.
The cap does not pro-rate
The 28 day ceiling is a ceiling on statutory entitlement, not a full-time figure that gets scaled down. A worker on a five day week reaches it exactly; a worker on six days does not get 33.6 days.
That means the cap has no effect at all on anybody working five days a week or fewer, which is almost all part-time staff. If a part-time calculation has invoked the cap, the calculation is wrong.