TTaxmiserSave more tax, legally

Built to save you money

IR35 calculator for contractors

If you contract through an agency or your own company, IR35 decides how your money is taxed. Put your real day rate in and see all three routes side by side, using published UK 2025/26 rates.

Status is not a choice. It depends on how you actually work, and for medium and large clients the client decides and must give you a written determination. This tool shows what each honest outcome costs, so you can plan and negotiate. It never suggests calling a contract outside IR35 when it is not.

Your figures

Everything starts at nothing. Each number below is one you type, and the example is clearly your choice.

Nothing entered yet, so nothing is owed

Add your day rate and the days you expect to bill, and the three routes will appear here. We will never fill in an income for you.

People are talking about tax now

A tax worry gets lighter when you can ask it.

Read openly, post under a nickname, or get a public answer from a verified professional. Every useful answer can save the next person money too.

Join the tax conversations