IR35 checklist for subcontract-heavy crews
Use Toolfy tasks, contracts, and evidence logs to prove your subcontractors are genuinely self-employed before HMRC comes asking.
Not tax advice
Toolfy shares operational guidance, but you must confirm CIS and HMRC requirements with a qualified accountant who understands your business.
IR35 checklist for subcontract-heavy crews
HMRC is reviewing labour-only subs again in 2026. If you rely on CIS subcontractors, keep this checklist handy so you can prove they’re outside IR35.
1. Contract essentials
- Use a written agreement that spells out substitution rights, pricing per job, and responsibility for tools/insurance.
- Store signed contracts in Toolfy Documents
/IR35/Subcontractors/{name}with version numbers.
2. Day-to-day evidence
| Factor | What HMRC wants | Toolfy evidence |
| --- | --- | --- |
| Control | Subs choose how/when they work | Job notes show deliverables, not step-by-step instructions |
| Financial risk | Subs fix defects at their cost | Tasks tagged Remedial assigned to the sub |
| Equipment | Subs bring their own kit | Checklist item confirming they supplied tools |
3. Checklist
- Verify UTR + CIS status annually; upload screenshots to Toolfy.
- Collect insurance certificates and set renewal reminders.
- Log instances where the sub sent a replacement worker (proves substitution).
- Avoid paying day rates inside Toolfy invoices—stick to price per job/phase.
4. Internal audit cadence
- Quarterly, export all subcontractor jobs and sample 5 to ensure evidence is attached.
- Document the audit in Toolfy (task board + summary note) so you can show HMRC you checked proactively.
Need contract templates or the audit board? Email support@toolfy.io for the pack.
⚠️ Important Disclaimer
This guide is for general informational and educational purposes only. It does not constitute professional advice of any kind (legal, financial, tax, insurance, or otherwise).
Before making business decisions: Consult with qualified professionals (solicitors, accountants, insurance brokers, etc.) who can assess your specific circumstances. Laws, regulations, and industry standards change frequently and vary by location and situation.
Toolfy and the article authors accept no liability for decisions made or actions taken based on information provided in this guide. You are solely responsible for ensuring compliance with all applicable laws and regulations.
Frequently Asked Questions
What evidence proves a subcontractor is outside IR35?
What should a subcontractor contract include for IR35 compliance?
How often should I audit subcontractor IR35 compliance?
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