IR35 basics for locums

Updated Sun, 14 Jun 2026

IR35 (the off-payroll working rules) is tax legislation about whether someone working through an intermediary — such as their own limited company — is really acting like an employee. It exists to stop "disguised employment".

Does it apply to me?

• If you work as a sole trader invoicing pharmacies directly, IR35 in its off-payroll form generally isn't the mechanism that applies — but your employment status for tax can still be questioned by HMRC.
• If you work through your own limited company, the off-payroll rules can be relevant, and responsibility for assessing status may sit with the engager.

Why it matters

Getting status wrong can lead to unexpected tax and National Insurance bills. The rules are nuanced and depend on how you actually work — not just the label on a contract.

Where to get proper advice

This is a simplified overview, not tax advice. IR35 is genuinely complex — speak to an accountant who knows locum/healthcare work and check the current HMRC guidance before relying on any position.