About Payroll Explained

Payroll Explained is an independent technical blog about UK payroll. It covers how the system actually works under the hood: Real Time Information (RTI), benefits in kind, National Insurance, tax codes, and the HMRC specifications that payroll software is built against.

Everything here is written from primary sources - GOV.UK guidance, HMRC technical specifications, and legislation - rather than second-hand summaries. Where a calculation matters, it's worked through step by step.

Who writes this

Sam Brown - a software developer, not an accountant. The posts here come from having to understand HMRC's specifications well enough to build against them, and writing down what that took: the primary sources, the worked examples, and the places where the documentation doesn't quite say what it means.

Nothing on this site is tax or legal advice. Always check GOV.UK or a qualified adviser for decisions that affect you or your business.

Contact

Spotted an error or want a topic covered? Email hello@payrollexplained.uk.