Disclaimer: IR35 Calculator

Last updated: June 2026

We built this tool to be genuinely useful. But useful does not mean infallible. Before you make any decision based on what the calculator tells you, there are a few things worth knowing. This page explains exactly what our tool does, where its limits are, and what you should do next.

The calculator gives you an estimate, not a guarantee

The IR35 Calculator works out an approximate take-home pay figure based on the numbers you put in. That is all it does.

The results are based on current UK tax rates, National Insurance thresholds and standard assumptions about how income is structured. They are a useful starting point. They are not a precise reflection of your personal tax position.

Your actual take-home pay may differ. It will depend on things like what you pay into a pension, what you pay on a student loan, other income you have, and details of your contract that the calculator cannot take into account.

This is not professional tax or legal advice

IR35 is a complicated area of UK tax law. The rules shift. HMRC guidance gets updated. What applies to one contractor may not apply to another. Individual circumstances matter enormously, and a general online tool cannot weigh those up for you.

If you are making a real decision — whether to take a contract, how to structure your income, or whether you are inside or outside IR35 — please speak to a qualified accountant or tax adviser first. That conversation is worth far more than any calculator result.

We do not confirm your IR35 status

The calculator does not determine whether you are inside or outside IR35. It only shows you the financial difference between the two scenarios.

What can confirm your status?

HMRC runs a free tool called Check Employment Status for Tax. It asks questions about your working arrangements and gives a determination. It is not perfect — it has known limitations around mutuality of obligation — but it is the official starting point.

For anything more definitive, an independent IR35 specialist or employment tax adviser can assess your actual contract and working practices. Our IR35 checker guide explains how that process works.

Tax rates and figures may be out of date

We update the calculator when tax rates, thresholds and National Insurance bands change. But there is sometimes a gap between a change being announced and us getting the update live.

Do not rely on this tool as your only source for current HMRC figures. Always cross-check against the latest rates published directly by HMRC.

We are not responsible for decisions you make

We provide this website and the IR35 Calculator free of charge. Because of that, and because the results are estimates based on general assumptions, we cannot accept responsibility for any financial loss, tax liability or other consequence that arises from using this tool.

That is not us trying to dodge accountability. It is a straightforward reflection of what this tool is: a free general-purpose calculator, not a professional service.

Your decisions are your own. We strongly recommend getting proper advice before acting on anything you work out here.

External links on this site

We link to external websites from time to time, including government resources and HMRC tools. We do not control those sites and cannot be held responsible for their content, accuracy or availability. Once you leave this site, this disclaimer no longer covers you.

How this fits with our other legal pages

This disclaimer sits alongside our terms and conditions, which cover how the site works, what you can and cannot do here, and the limits of our liability in more detail.

Got a question?

If something here is unclear, or you have spotted a figure that looks wrong, please get in touch. Email hello@ir35calculator.co.uk. We aim to respond within 5 working days.