CIS Deductions & Refund Checklist 2026/27
Check your CIS deductions are right, keep the paperwork HMRC expects, and get back any tax you've overpaid. 2 pages, plain English, free.
Free: CIS Deductions & Refund Checklist
Check every CIS deduction is right, keep the right paperwork and see if you're owed money back. 2 pages, plain English.
Just want to read it? It's all below. Open the PDF (2 pages, A4).
1. Are you on the right rate?
| 20% | You're registered for CIS and the contractor can verify you. |
| 30% | You're not registered, or the contractor can't verify you. Register to drop to 20%. |
| 0% | You have gross payment status: paid in full, and you pay your own tax later. |
- I've registered for CIS (you need your UTR from HMRC).
- I gave each contractor my exact registered name and UTR, so they can verify me.
- My statements show 20% (or 0%), not 30%.
2. Check every deduction
CIS should only come off your labour. It should not come off:
- VAT
- Materials you paid for yourself (keep the receipts)
- Plant hired for the job
- Consumables that get used up on the job
Labour £1,000 + materials £300 = invoice £1,300
CIS: 20% of £1,000 = £200 (not £260)
You're paid £1,300 − £200 = £1,100
- Materials are on their own line on my invoice.
- I've kept receipts for materials (the contractor can ask for them).
3. Keep your paperwork
- A payment and deduction statement for every month I was paid. The contractor must give it within 14 days of the end of each tax month (tax months end on the 5th).
- A copy of every invoice I sent.
- Receipts for expenses: tools, van, fuel or mileage, phone, workwear and protective kit, insurance.
- If a statement is missing or wrong, I've asked the contractor for it.
4. Claim back what you've overpaid
CIS deductions are advance payments towards your tax and National Insurance. The 20% comes off before your expenses and before your £12,570 Personal Allowance, so many subcontractors are owed money back.
- After the tax year ends (5 April), I send my Self Assessment return. (Sole traders. Limited companies claim through payroll instead.)
- I put my total pay before deductions as income.
- I put the total CIS taken off in the CIS deductions box.
- I include my bank details so HMRC can pay any refund.
- If I owe more, I pay it by 31 January.
5. Thinking about 0% (gross payment status)?
As a sole trader you'll usually need turnover of at least £30,000 in the last 12 months (not counting VAT and materials), a business bank account, and a record of paying tax on time. HMRC checks every year.
Quick tools: CIS calculator (billmyweek.com/cis-calculator) and CIS refund checker (billmyweek.com/cis-refund-checker).
Sources
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