How CIS works
Under the Construction Industry Scheme, contractors take money off your payments and pass it to HMRC. If you’re registered, they deduct 20%. If you’re not, it’s 30%. These deductions count as advance payments towards your tax and National Insurance.
If you don’t want deductions taken in advance, you can apply for gross payment status.
Could you be owed a refund?
Often, yes. The amount deducted can be more than your real tax bill once your costs are taken off. When it is, you can claim the difference back through your self assessment return. We work it out and tell you the figure.
Costs you can claim
You’re taxed on profit, so costs matter. Typical ones for subcontractors are tools, protective clothing, van costs, materials you buy yourself, insurance and phone costs. Keep the receipts.
Making Tax Digital
Making Tax Digital for Income Tax applies to self-employed income over £50,000 from April 2026, over £30,000 from April 2027 and over £20,000 from April 2028. If it applies to you, you send HMRC short updates each quarter.
What we need from you
- Your CIS payment and deduction statements
- Your invoices or a record of what you were paid
- Receipts for your costs
Sources
- CIS: what you must do as a subcontractor
- Construction Industry Scheme
- Expenses if you’re self-employed
- Self-employed National Insurance rates
- Making Tax Digital for Income Tax
Checked against GOV.UK on 11 October 2026. This is general information, not personal advice. Rates and rules change, so we confirm them for your own situation.