PayCaptain developer documentation
Build on PayCaptain
One API for UK payroll data. Send employees, shifts and pay elements in; read employees and payslips out. Every rule is published here, for people and for agents.
QuickstartField validationllms.txt
- HMRC recognised
- ISO 27001
- Cyber Essentials Plus
What you can do#
| You want to | Use | Field rules |
|---|---|---|
| Create or update an employee | POST /employee |
Employee fields |
| Send approved shifts and absences | POST /shift |
Shift fields |
| Send bonuses, expenses and other pay elements | POST /payment |
Payment fields |
| Read employees back | GET /employees |
Employee fields |
| Read payslips for a pay period | GET /payslips |
Payslip fields |
New here? The Quickstart takes you from API key to first accepted record.
How it fits together#
Your application is the system of record for people, attendance and pay elements. PayCaptain is the payroll engine. Records flow one way, through a validation layer you own, and payslips flow back.
Your application -> Your validation layer -> PayCaptain
employees field rules POST /employee
shifts business rules POST /shift
pay elements change detection POST /payment
payslip viewer <- ------------------------ GET /payslips, GET /employees
Must Validate before you send. PayCaptain rejects invalid data, but it is not your validation service. Enforce the field rules and business rules in your own code, and only then call the API.
Trust, in practice#
PayCaptain is HMRC-recognised payroll software with a direct connection to UK banking services, certified to ISO 27001 and Cyber Essentials Plus. Payroll only works when everyone can rely on it, so this site is built to be checked rather than believed.
- Every rule is written down. Each field has its type, format, allowed values and conditions on one page. If the API rejects something for a reason that is not documented here, tell us and we will document it.
- One source for people and agents. Every page is also plain Markdown, and the field rules ship as JSON Schema and OpenAPI. All of it is generated from the same data, so the copies cannot drift apart.
- Clear responsibilities. PayCaptain's core is operated by PayCaptain UK personnel. Your integration comes in through one authenticated door, and Trust and security sets out what we do and what you must do.
- No trackers on this site. No cookies, no analytics scripts, no third-party requests.
Open to the way you work#
- Customers connect the HR, rota and time systems they already run, or build their own.
- Payroll teams stay in control. Pay Groups, Pay Codes and approvals are configured in PayCaptain, and the API respects them.
- Partners build one integration and offer it to every shared customer.
- AI builders and agents get the same rules in machine-readable form. See Build with AI.
More endpoints are available on request. Email developer@paycaptain.com to discuss what you need, or to get your API key and company code.