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United Kingdom · Tax year 2026/27

IR35 Calculator & Status Checker

Two tools in one: check whether your contract looks inside or outside IR35 using the HMRC tests, then compare your take-home pay both ways. Everything runs in your browser — nothing is stored.

1. Are you inside or outside IR35?

Answer six questions about how you actually work. The big three — substitution, control and mutuality of obligation — carry the most weight, exactly as an HMRC assessment would.

  1. Key test 1. Substitution — can you send a qualified substitute to do the work?

  2. Key test 2. Control — who decides how, when and where you work?

  3. Key test 3. Mutuality of obligation — must the client offer work and must you accept it?

  4. 4. Financial risk — do you risk your own money (fixing mistakes unpaid, buying equipment, quoting fixed prices)?

  5. 5. Part and parcel — are you treated like one of the client's employees (line management, staff perks, company email, fixed role)?

  6. 6. Exclusivity & equipment — do you work for multiple clients and use your own equipment?

2. Inside vs outside IR35 take-home

Enter your day rate to estimate annual take-home pay both inside and outside IR35 for the 2026/27 tax year (England). See the assumptions below the result.

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Estimate only — read the assumptions. Outside IR35 assumes a £12,570 director's salary plus dividends through your own limited company (corporation tax with marginal relief, 2026/27 dividend rates). Inside IR35 assumes an umbrella/deemed-employment PAYE basis with employer's NI (15% above £5,000) and the 0.5% apprenticeship levy deducted from the assignment rate. England tax bands; no student loan, pension or other reliefs. This is not financial or tax advice — see our disclaimer.

How the IR35 status test works

IR35 (also called the off-payroll working rules) exists to stop “disguised employment” — where someone works through a limited company but behaves day-to-day like an employee of the client. If your working arrangement looks like employment, HMRC says you're inside IR35 and your income from that contract should be taxed broadly like a salary. If you operate like a genuine business, you're outside IR35 and can pay yourself tax-efficiently through a mix of salary and dividends.

There's no single deciding factor. HMRC and the courts weigh the whole picture, but three tests do most of the work:

  • Personal service / substitution. A genuine, unfettered right to send a substitute is one of the strongest pointers to outside IR35. If you must do the work personally, that points inside.
  • Control. The more the client dictates how, when and where you work, the more it looks like employment. Autonomy over your methods points outside.
  • Mutuality of obligation (MOO). If the client must keep offering you work and you must accept it, that ongoing obligation looks like employment. A contract for a defined piece of work points outside.

Secondary factors — financial risk, whether you're “part and parcel” of the organisation, exclusivity and providing your own equipment — can tip a borderline case either way. Our checker weighs the three main tests more heavily than these supporting factors, then gives you an indication, not a determination.

What inside vs outside IR35 means for your pay

The financial gap is the reason IR35 matters so much. Outside IR35, a contractor typically takes a small salary up to the personal allowance and draws the rest as dividends, which carry lower tax rates and no National Insurance. Inside IR35, the income is treated as deemed employment: income tax and employee National Insurance apply through PAYE, and the fee-payer also has employer's National Insurance and the apprenticeship levy to fund from the assignment rate.

In practice an inside-IR35 day rate usually needs to be around 15–20% higher than an outside one to leave you with similar net pay. The calculator above shows the gap for your own numbers so you can negotiate from an informed position.

The April 2026 small-company change

Since April 2021, for medium and large private-sector clients it's the client who decides your IR35 status and issues a Status Determination Statement. But small private-sector clients are exempt: responsibility for assessing status stays with your own company. From April 2026, the thresholds that define a “small” company changed, so some clients that previously had to assess status no longer do for 2026/27 — which can hand the decision back to you. A client is small if it meets two of: turnover ≤ £10.2m, balance sheet ≤ £5.1m, and ≤ 50 employees.

Frequently asked questions

What is IR35?

IR35 is UK tax legislation that decides whether a contractor working through their own limited company should be taxed like an employee (inside IR35) or as a genuine business (outside IR35). Being inside IR35 typically reduces take-home pay by 20–30% because income is taxed through PAYE.

How do I know if I'm inside or outside IR35?

HMRC looks mainly at three tests: substitution (can you send someone else to do the work?), control (does the client dictate how, when and where you work?) and mutuality of obligation (must the client offer work and must you accept it?). No single factor decides it — it's the overall picture. Our status checker weighs your answers to these tests to give an indication.

How much does being inside IR35 cost me?

It varies with your day rate, but an inside-IR35 engagement usually needs to pay roughly 15–20% more than an outside one to leave you with the same net pay. Use the take-home calculator above to see your own figures.

What changed for IR35 in April 2026?

From April 2026 the company-size thresholds that define a 'small' client changed. Some clients that were previously in scope of the off-payroll rules fall outside them for the 2026/27 tax year, which can move responsibility for the status determination back to the contractor's own company.

Is my client a 'small company' for IR35?

A private-sector client is small if it meets two of: turnover not more than £10.2m, balance sheet total not more than £5.1m, and no more than 50 employees. If your client is small, responsibility for determining your IR35 status stays with your own limited company rather than the client.

Who is responsible for deciding my IR35 status?

For medium and large private-sector clients, since April 2021 the end client decides your status and issues a Status Determination Statement; the fee-payer (client or agency) then deducts the right tax. For small private-sector clients, responsibility stays with your own limited company. In the public sector, the client always decides.

How can I stay outside IR35?

Make sure your contract and your actual working practices reflect a genuine business: a real right of substitution, control over how, when and where you work, no obligation on either side to offer or accept ongoing work, your own equipment, and not being treated as 'part and parcel' of the client's organisation. Keep evidence, and review your status whenever a contract changes.

This tool gives an indication based on the information you provide and general 2026/27 rules. It is not a Status Determination Statement and is not financial, tax or legal advice. For an important contract, get a professional IR35 review. Figures are estimates — see our disclaimer.