How to Start a Payroll Bureau in the UK: A Complete Guide
Starting a payroll bureau is one of the most reliable ways to build a recurring-revenue services business. Every employer in the country has to run payroll every month, most would rather not do it themselves, and the work is sticky — once a client trusts you with their pay run, they rarely leave. This guide walks through how to start a payroll bureau in the UK, from registration to your first clients.
What a payroll bureau actually does
A payroll bureau processes payroll on behalf of other businesses. You collect each client's hours, salaries, starters, leavers, and adjustments, calculate PAYE income tax and National Insurance, produce payslips, file Real Time Information (RTI) submissions to HMRC, and tell the client what to pay their staff and HMRC. Many bureaus also handle pension auto-enrolment, statutory payments, and year-end reporting.
Step one: get the legal and HMRC basics right
You can operate as a sole trader, partnership, or limited company. Most bureaus incorporate for liability protection. You will need to register with HMRC as an agent so you can file RTI and access clients' PAYE schemes on their behalf — this means setting up an agent services account and an online agent account.
Because you are handling personal and financial data, you must register with the Information Commissioner's Office (ICO) for data protection, and you should put a written data processing agreement in place with each client. Professional indemnity insurance is effectively mandatory: a single payroll error across a 200-person client can be expensive.
Step two: choose your payroll bureau software
Your software is your business. You need genuine multi-client payroll software — a platform built to manage many client companies from one place, not a single-company tool you re-license over and over. Look for:
- A client switcher so you can move between companies in one login
- Cross-client compliance and RTI submission tracking
- Practice team roles so staff only see the clients they work on
- Reporting that works across your whole client base
Mellow's Practice (Bureau) mode is built for exactly this: one login manages many client companies, you add clients as you win them, and you run payroll, compliance, employees, and reports for every client from a single dashboard.
Step three: decide what you charge
Bureau pricing is usually a base fee per client per pay run plus a per-payslip charge. Decide whether you bill monthly, weekly, or per-frequency, and whether extras (P45s, year-end, auto-enrolment assessments) are bundled or charged separately. Our payroll bureau pricing guide goes into detail.
Step four: nail compliance from day one
As a bureau you are responsible for filing RTI on or before each client's pay day, handling auto-enrolment duties, and keeping accurate records. The risk multiplies across clients — a missed deadline is no longer one fine, it is potentially dozens. Choose a platform that shows you, in one view, which clients have been filed and which are outstanding.
Step five: win your first clients
Most bureaus start with warm contacts — existing bookkeeping or accountancy clients, local businesses, referrals from accountants who do not want to run payroll themselves. Bookkeepers are a natural feeder: many of their clients already ask them to "just sort the wages too". Position yourself as the reliable, compliant, never-misses-a-deadline option.
Where bureaus go next
The smartest bureaus do not stop at processing. Because you already hold every client's employee data, you are uniquely placed to offer HR advisory services — employment law guidance, compliance alerts, and people insight — turning a low-margin processing business into a higher-margin advisory practice. More on that in why payroll bureaus should offer HR advisory services.
Starting a payroll bureau is achievable for anyone with payroll knowledge, the right multi-client platform, and the discipline to never miss a filing deadline. Get those three things right and the recurring revenue follows.