All calculators

CIS Tax Deduction Calculator

Estimate the deduction and payment for a subcontractor invoice under the Construction Industry Scheme.

Go to the calculator

Check the deduction status first

For 2026/27, CIS deductions are 20% for registered subcontractors, 30% for unregistered subcontractors and zero where HMRC confirms gross payment status. Use the status given by HMRC when you verify the subcontractor.

We subtract the permitted costs from the invoice before VAT, then apply the deduction rate. Add only VAT that is actually payable to the subcontractor. CIS deductions are payments towards tax, not a final tax bill.

Check the HMRC deduction rules for the costs you may exclude.

Tax year: 6 April 2026 to 5 April 2027. See our 2026/27 tax rates and sources. This is an estimate under the assumptions above, not a tax return or individual advice.

Calculations run in your browser. Your entries are not stored or sent to us.