IR35 Status Calculator

Determine your IR35 status with this 13-question CEST-style assessment and compare tax implications across different employment structures.

Legal Disclaimer

This tool does NOT provide legal or tax advice. IR35 determinations are complex and fact-specific. This calculator provides educational guidance only.

Always consult a qualified accountant, tax adviser, or legal professional for IR35 determinations. HMRC's official CEST tool is available at gov.uk/guidance/check-employment-status-for-tax.

IR35 Assessment Questionnaire

Question 1/13
Substitution - Question 1

Would your contract allow you to send someone else to complete the work instead of you?

Substitution - Question 2

If you send a substitute, must the client accept them without question?

Substitution - Question 3

If you use a substitute, would you pay them from your own fees?

Substitution - Question 4

Have you actually used a substitute, or could you realistically do so under your contract?

Control - Question 5

Does the client specify the tasks and deliverables, or do you decide based on the outcome needed?

Control - Question 6

Does the client control the methods, processes, or approach you use to complete the work?

Control - Question 7

Must you work specific hours set by the client, or can you choose your own schedule?

Control - Question 8

Must you work at the client's premises, or can you work from your own location?

Control - Question 9

Does someone from the client supervise or direct your day-to-day work?

Mutuality of Obligation - Question 10

After this contract ends, must the client offer you more work?

Mutuality of Obligation - Question 11

If the client offers you work, must you accept it?

Mutuality of Obligation - Question 12

Do you receive benefits like sick pay, holiday pay, pension contributions, or other employee perks?

Mutuality of Obligation - Question 13

Can the client end the contract immediately or with short notice without paying compensation?

Frequently Asked Questions

IR35 is UK tax legislation designed to combat tax avoidance by workers who supply their services through an intermediary (usually a limited company) but would be considered employees if the intermediary wasn't there. If caught inside IR35, you pay similar tax and National Insurance as an employee, losing limited company tax benefits.

If your contract is inside IR35, you must pay Income Tax and National Insurance as if you were an employee. Your client (if medium/large) deducts tax at source. You lose tax benefits of dividend payments and cannot claim many business expenses. This significantly reduces your take-home pay compared to working outside IR35.

This tool provides guidance based on HMRC's Check Employment Status for Tax (CEST) principles, but it is NOT a substitute for professional advice. IR35 determinations are complex and fact-specific. A BORDERLINE result means you should definitely seek professional tax or legal advice before proceeding.

Since April 2021, medium and large private sector clients (and all public sector clients since 2017) must provide contractors with a Status Determination Statement explaining whether a role is inside or outside IR35 and why. The client is liable for the decision. Small companies are exempt - contractors determine their own status.

Yes. If your client provides an SDS you disagree with, you can challenge it. The client must respond within 45 days. If still unresolved, you may need professional advice or potentially take legal action. For self-determinations (small clients), you can request an HMRC review, but professional advice is strongly recommended first.
About IR35
What is IR35?

IR35 is anti-avoidance tax legislation affecting contractors who work through their own limited company or personal service company.

Key Tests
  • Substitution: Can you send someone else?
  • Control: Who controls what, how, when, and where you work?
  • Mutuality of Obligation: Is there an ongoing employment relationship?
Who Decides?

For medium/large clients: the client decides and provides an SDS. For small clients: you decide your own status.

Important Notes
  • This tool provides guidance only, not legal advice
  • BORDERLINE results require professional consultation
  • IR35 status depends on working practices, not just contract terms
  • Each contract must be assessed individually
  • Penalties for incorrect status can be significant
Useful Resources