UK CIS · Refund & statement guide
CIS refund for Self-employeds
How the Construction Industry Scheme deduction works for self-employeds, your deduction statement, and whether you're owed money back.
Skip the reading — get your statement and a refund estimate
Enter what you were paid, the materials portion, your deduction rate and expenses. In about 20 seconds you get an HMRC-format CIS deduction statement plus an indicative refund figure. Free, no account.
Generate your HMRC-format statement + refund estimate →What CIS means for self-employeds
If you're self-employed in construction and paid under CIS, those deductions are advance payments toward your Income Tax and Class 4 NI. You still file a Self Assessment return, and once your allowable expenses and personal allowance are taken into account, the CIS already withheld often exceeds what you actually owe — which is where a refund comes from.
How CIS deductions and statements work
- Deductions come off labour, not materials.CIS is taken from the labour portion of a payment — the verified materials part is excluded — at 20% for registered subcontractors or 30% for those HMRC can't verify.
- Contractors must issue a deduction statement within 14 daysof the end of each tax month (the 5th), showing the gross amount, the materials deducted, and the CIS withheld. Keep every statement — it's your proof of tax already paid.
- Subcontractors with 20% withheld are often owed a refund. The deduction is taken before your allowable expenses and personal allowance, so once you file Self Assessment the tax already paid frequently exceeds what you actually owe.
- Registering is worth it. The gap between the 30% unregistered rate and the 20% registered rate is money withheld from your cash flow all year until you reclaim it.
Want your own numbers?
Plug in your figures — the tool builds a clean CIS deduction statement and shows whether, on an indicative year-end view, you're likely owed a refund.
Generate your statement + refund estimate →Indicative, not tax advice. The refund figure uses simplified illustrative tax/NI bands, not your full circumstances. Confirm your statement format and any refund with HMRC or a qualified accountant before you rely on it.
Claim your refund
When you want the refund actually filed, or your CIS bookkeeping handled year-round:
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CIS refund & deduction statement FAQs for self-employeds
I'm self-employed in construction — do I still file Self Assessment if CIS was deducted?
Yes. CIS deductions are advance payments, not a final tax settlement, so you still submit a Self Assessment return. On that return you set the CIS already withheld against your actual Income Tax and Class 4 NI once expenses and your personal allowance are counted — that comparison is where any refund (or balance owed) is worked out. Confirm the specifics for your situation with HMRC or an accountant.
Are CIS deductions taken from the whole payment, including materials?
No — CIS is deducted only from the labour portion of a payment. The verified cost of materials is excluded before the deduction is applied. If materials are not evidenced correctly, more of the payment can be treated as labour, so keep clear records of the materials element and confirm the treatment with HMRC.
What's the difference between the 20% and 30% CIS deduction rates?
The 20% rate applies to subcontractors who are registered for the Construction Industry Scheme and can be verified by HMRC. The 30% rate applies where a subcontractor is not registered or cannot be verified. Registering can reduce the amount withheld from your cash flow during the year. Check your registration status and current rates with HMRC.
How do I actually claim a CIS refund back from HMRC?
A refund is claimed through your Self Assessment return after the tax year ends, using your CIS deduction statements as proof of tax already paid. Once your income, expenses and allowances are entered, any overpayment can be repaid or set against what you owe. HMRC sets the process and timing, so confirm the current steps with HMRC or use an accountant to file on your behalf.
What if I've lost a CIS deduction statement?
Ask the contractor who made the deduction to reissue the statement — they are required to keep records of payments and deductions. Your own bank records and invoices can help reconcile the figures, but the statement is your primary evidence of tax withheld. For missing or disputed amounts, confirm the position with HMRC.
General guidance only, not tax advice. CIS rules, rates and deadlines can change — confirm anything specific to your circumstances with HMRC or a qualified accountant.