Use our free IR35 status determination tool to check whether your contract is likely to fall inside or outside IR35. The tool evaluates key status indicators used by HMRC and employment tribunals, including substitution rights, client control, mutuality of obligation, financial risk and business independence.
You'll receive an instant compliance score, evidence assessment, risk heatmap and practical recommendations to help strengthen your position and understand potential IR35 exposure.
Results are for general guidance only and do not constitute tax, legal, accounting or IR35 advice; professional advice should be sought before making decisions based on this assessment. For additional guidance, you may also wish to complete HMRC's official Check Employment Status for Tax (CEST) tool: Check your IR35 status using HMRC CEST.
If you sent a qualified substitute tomorrow, what would happen?
How are daily tasks actually allocated?
Please supply inputs to evaluate risk indices across substitution, MoO, and structural framework parameters.
| Indicator | Evidence HMRC Would Expect |
|---|---|
| Substitution | Contract clause, signed substitute agreement, timesheets of substitute. |
| Multiple Clients | Invoices to different clients, concurrent contracts, bank statements. |
| Financial Risk | Professional Indemnity Insurance schedule, documented rectification clauses. |
| Business Profile | Live company website, active marketing footprint, dedicated office lease. |
HMRC conducts compliance enquiries based on demonstrable facts, not just assertions. The Defensibility Score combines your working practices profile (75%) with your ability to evidence it (25%).
Run the assessment to generate your personalised contract improvement plan.
Run the assessment to view predicted HMRC compliance enquiry failure points.
Your assessment indicates an Outside IR35 status. This means you are recognised as an independent business providing a service, rather than a disguised employee. To maintain this status defensively against HMRC compliance reviews:
Your assessment indicates a Borderline status. HMRC regularly scrutinises borderline relationships. To protect yourself:
Your assessment indicates an Inside IR35 status. This implies that HMRC would likely view you as an employee for tax purposes during an enquiry, subjecting your income to standard PAYE Income Tax and National Insurance deductions.
This IR35 diagnostic tool is provided for indicative educational and informational purposes only. The generated scores, heatmaps, and remediation plans do not constitute formal tax, legal, or accounting advice. HMRC status determinations are highly nuanced and depend on the totality of specific contractual facts and actual working practices. Always consult a qualified contractor accountant, IR35 specialist, or employment lawyer before making financial decisions or signing contracts.
IR35, officially known as the Off-Payroll Working rules, is tax legislation introduced by HMRC to identify "disguised employees." These are individuals who operate via an intermediary—such as a personal service company (PSC) or limited company—to reduce tax liabilities, while working in a manner indistinguishable from permanent staff members.
Your IR35 status fundamentally dictates how you are taxed. If you operate Outside IR35, you are treated as a genuine business. You can pay yourself a tax-efficient combination of salary and dividends. If your contract is deemed Inside IR35, you are taxed at source as an employee via PAYE, significantly reducing your net take-home pay.
The rules apply to any contractor, freelancer, or consultant providing services through their own limited company to an end client in the UK. Since the legislative reforms of 2017 (Public Sector) and 2021 (Private Sector), medium and large clients are responsible for determining your status, while small business contractors must still self-determine.
This tool evaluates your working relationship against the core pillars established by decades of UK employment tribunals and case law precedent. It looks past the written contract to assess the day-to-day reality of your engagement, generating a defensibility score and actionable recommendations.