Calculate Your CIS Deductions
Enter your invoice details below
What Happens to CIS Deductions?
CIS deductions aren't lost money — they're advance payments towards your tax bill. When you do your Self Assessment, these deductions are credited against your income tax liability.
If more CIS has been deducted than you owe in tax, you'll get a refund from HMRC.
Disclaimer: This calculator provides estimates for guidance only. Always consult with a qualified accountant for tax advice. CIS rules may change — verify current rates with HMRC.
Understanding CIS Tax
The Construction Industry Scheme (CIS) requires contractors to deduct tax from subcontractor payments before paying them. This affects builders, plumbers, electricians, and most trades working on construction projects.
CIS Deduction Rates
20% (Registered): If you're registered with HMRC for CIS, contractors deduct 20% from your labour charges.
30% (Unregistered): If you're not registered, the deduction is 30% — a strong incentive to register.
0% (Gross Status): Some established businesses can apply for gross payment status, meaning no deductions. You need a good compliance history to qualify.
What Counts as Materials?
CIS is only deducted from labour costs, not materials. If your invoice clearly separates materials and labour, the contractor should only apply CIS to the labour portion. Keep clear records and receipts for all materials.