IR35 Status Assessment Tool 2026

The problem: getting IR35 wrong is expensive for everyone

Over 2 million UK contractors operate through personal service companies. Since April 2021, medium and large businesses must determine their contractors' IR35 status and take "reasonable care" doing so. Contractors caught inside IR35 lose 20-30% of their contract value. Businesses that make blanket determinations risk HMRC challenge and chain liability. HMRC's own CEST tool is widely criticised by tribunals.

• Specialist IR35 advisers charge £200-500 per assessment
• HMRC's CEST tool doesn't adequately assess mutuality of obligation, its results aren't binding on tribunals
• Blanket inside-IR35 determinations expose businesses to contractor disputes and loss of talent
• Contractors who don't understand their own position can't challenge wrong determinations

Built on real case law

• Ready Mixed Concrete v MPNI [1968] - the three-part test: MOO, control, personal service
• Autoclenz v Belcher [2011] - substance over form, actual working practices matter
• Pimlico Plumbers v Smith [2018] - substitution must be genuine, not just contractual
• Hall v Lorimer [1994] - paint the picture from all factors together
• HMRC v Atholl House [2022] - mutuality of obligation assessed per engagement
• Professional Game Match Officials v HMRC [2024] - control in detail

Assessment outputs

• Factor-by-factor analysis across all 10 employment status indicators
• Risk rating (HIGH / MEDIUM / LOW) with confidence score
• Contract amendment recommendations, specific clause changes to strengthen your position
• Working practice recommendations, practical changes that shift the balance
• Status Determination Statements for medium and large businesses
• CEST comparison, where and why this assessment may differ from HMRC's tool
• Dispute response support for challenging an inside-IR35 determination