UK · IR35 tools
A clearer alternative to HMRC's CEST tool
HMRC's Check Employment Status for Tax (CEST) tool is the official way to test IR35 status — but it's famously blunt. It often returns “Undetermined”, ignores mutuality of obligation, and gives little plain-English explanation. Our IR35 status checker is built to be the friendlier companion: it always gives you a direction, explains why, and shows what each outcome does to your take-home pay.
What CEST does well — and where it falls short
CEST has real advantages: it's free, it's official, and HMRC says it will stand by the result if your answers are accurate and reflect reality. For a clear-cut contract, that's reassuring. But contractors and accountants have long flagged its weaknesses:
- “Undetermined” results. A significant share of assessments come back inconclusive, leaving you no better off.
- It downplays mutuality of obligation (MOO). CEST largely assumes MOO exists, even though it's one of the three pillars the courts actually weigh.
- Little explanation. You get an outcome, not an education — so you can't easily see which answers drove it.
- No financial picture. CEST tells you a status, never what inside vs outside means for your pay.
How our IR35 status checker differs
| Feature | HMRC CEST | Our checker |
|---|---|---|
| Always gives a direction | Often “Undetermined” | Yes — inside / borderline / outside |
| Weighs mutuality of obligation | Limited | Yes, as a core test |
| Plain-English explanation | Minimal | Explains the “why” |
| Shows take-home impact | No | Inside vs outside, side by side |
| 2026 small-company rules | Not built in | Built-in branch |
| Official / legal standing | Yes (HMRC) | Indicative only |
Use both — here's the smart workflow
These tools aren't rivals; they're better together. Use our checker first to understand your position in plain English and see the money at stake. Then, for a contract you intend to rely on, run CEST too and keep the result, because it carries HMRC's backing when your answers are accurate. For anything borderline or high-value, get a professional contract review as well — no automated tool replaces a specialist reading your actual working practices.
Important: our checker gives an indication, not a Status Determination Statement, and has no legal standing. CEST is the official tool. See our disclaimer.
Try the clearer checker
Answer six questions, get a plain-English IR35 verdict, and see your inside-vs-outside take-home for 2026/27 — free, no sign-up.
Open the IR35 status checkerGeneral guidance only, not financial or legal advice. CEST is provided by HMRC; we are not affiliated with HMRC. See our disclaimer.