CIS Tax & Refund Calculator
Enter your labour, materials and costs. We check the CIS that should have been taken, estimate your tax bill, and show whether you may be due a refund.
Private by designEverything runs in your browser.
Materials check includedFlags CIS that looks like it was taken on materials.
Working shownEvery figure in your estimate is broken down.
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Estimate only — not tax advice. This calculator uses simplified UK rates for England, Wales & Northern Ireland, assumes materials cost equals materials reimbursed, and does not cover student loans, pension, other income, Scottish tax, limited companies (company CIS offset works differently), payments on account, voluntary Class 2 contributions, or CIS suffered in a different year. Your actual bill depends on your full Self Assessment. Verify with HMRC or a qualified accountant. The figures you enter stay in your browser and are not stored.