A settled working week
The worker has fixed hours. Their leave is simply administered in hours rather than days.
POST /v1/entitlement/hours
A 25‑hour, five‑day part‑timer gets 5.6 weeks of their own working week.
Holiday entitlement, with the working attached.
A UK statutory holiday entitlement and holiday pay API for HR, workforce and payroll platforms. Seven calculations, every ruleset keyed to the date it took effect.
Week 1 of the leave yearWeek 52
5.6weeks of statutory leave in every leave year, under regulations 13 and 13A.
46.4weeks left to work, which is where an irregular‑hours accrual rate comes from.
12.07%is 5.6 ÷ 46.4, rounded. Regulation 15B sets it for leave years starting on or after 1 April 2024.
Every answer shows how it got there
Move the slider. This is the working the API returns for an irregular‑hours worker, calculated here the same way: exact arithmetic, rounded once, at the end.
Every response carries it as calculation_basis, alongside the ruleset_effective_date it was answered under.
Accrual rate× 12.07%Regulation 15B
Raw accrual301.75 hours
RoundingUpTo the nearest hour. 30 minutes or more rounds up.
Accrued302 hours
POST /v1/entitlement/irregular-hours
Two rules that look alike
Most of what you are buying is knowing which one applies.
No settled week at all
Irregular‑hours and part‑year workers, accruing 12.07% of the hours they actually work.
POST /v1/entitlement/irregular-hours
Regulation 15B, in force for leave years starting on or after 1 April 2024.
Applying 12.07% to a fixed part‑timer understates their entitlement. The API will not choose between them for you: the answer depends on the worker’s contract, which the request does not carry.
The same trap sits in the pay pair. Both /pay/holiday-pay and /pay/pay-in-lieu involve a 52, and they are different 52s: one is a window of past paid weeks to average, the other is a divisor turning annual salary into a weekly rate. They coincide by convention, not derivation.
What you can call
Bearer auth on everything except /health. JSON in, JSON out, with the ruleset it was answered under.
Entitlement
- POST/v1/entitlement/fixed
Fixed‑hours workers, pro‑rated across a partial leave year
- POST/v1/entitlement/irregular-hours
Hours accrued by the 12.07% method
- POST/v1/entitlement/hours
Fixed‑schedule part‑timers and shift workers, leave counted in hours
Accrual
- POST/v1/accrual/to-date
The running balance as at a given date
- POST/v1/accrual/during-absence
Holiday accrued while off sick or on statutory leave
Pay
- POST/v1/pay/holiday-pay
52‑week reference period average, for pay that varies
- POST/v1/pay/pay-in-lieu
Payment in lieu of leave left untaken at termination
Rules
- GET/v1/rules
Every published ruleset
- GET/v1/rules/current
The ruleset in force today, machine readable
- GET/v1/rules/{effective_date}
The ruleset in force on any date
Old leave years keep their old answers
Ruleset of 1 April 2024
The one published today. A leave year that started under it is answered under it, however late you ask.
The next ruleset
Applies to leave years starting on or after its own date. Nothing already answered moves.
Every calculation resolves its ruleset from the leave year start rather than from today, so when new regulations ship, a leave year that began under the old ones still gets the answer it got then. That is what makes a bulk recalculation safe to run. Pin it explicitly with ruleset_date when you need to.
The rules endpoints return the rates, caps and rounding behaviour that produced a figure, so you can show where it came from. Contractual entitlement below the statutory minimum is accepted and flagged as below_statutory_minimum, never silently corrected.
Pricing
Metered per call. Prices are illustrative until launch.
Sandbox
Building the integration
Free
1,000 calls a month
- Every endpoint, every published ruleset
- Test keys only, no production data
- The worked examples the API is tested against
Production
One product, live customers
£99a month
50,000 calls, billed monthly
- Every endpoint, every published ruleset
- Live keys
- Ruleset changes announced before their effective date
Vendor
A platform calculating for many employers
£399a month
500,000 calls, billed monthly
- Every endpoint, every published ruleset
- Live keys, with the allowance a platform needs
- Ruleset changes announced before their effective date
Calls over the included allowance are £1.40 per thousand. Yearly billing is ten months for twelve.