The Construction Industry Scheme (CIS) requires contractors to deduct tax from your pay before handing it over — 20% if you're registered, 30% if you're not. This flat deduction doesn't account for your actual business expenses, which means most subcontractors end up overpaying.
Why you've probably overpaid
CIS deductions are calculated on your gross earnings — not your profit. But you have real costs: tools, materials, fuel, van, insurance, workwear. None of that is considered when your contractor deducts tax at source. When you file a Self Assessment return and claim those expenses, your taxable income drops — and the difference is your refund.
The average CIS refund we process is between £1,000 and £3,000. Some tradespeople receive significantly more.
What can you claim?
- Tools, materials and safety equipment
- Vehicle costs — fuel, insurance, servicing, or mileage rate (45p/mile)
- Workwear and protective clothing
- Phone bills (business use)
- Public liability insurance
- Accountant fees
You can also claim for up to 4 previous tax years. If you haven't filed for 2021/22, 2022/23, 2023/24 or 2024/25 — you can still get that money back.
What we charge
Our CIS Self Assessment service is £150 fixed price, all years. We handle filing, chase HMRC if there are delays, and make sure you're claiming everything you're entitled to.
Find out what HMRC owes you
Send us your CIS statements and we'll tell you your refund estimate — free, no commitment.