CIS deduction calculator
Estimate the deduction on the labour element after qualifying materials. Confirm the actual basis and rate before payment.
Rates checked:
Who should use this calculator
This free calculator is intended for freelancers, sole traders, contractors and small-business owners who need a quick planning figure before preparing or checking an invoice. It can also help clients and bookkeepers understand the arithmetic behind a quoted amount. Use the result as a review aid alongside the relevant agreement, source records and current official guidance, not as an automatic accounting or legal decision.
Calculator methodology
Deduct qualifying materials from the amount excluding VAT, then multiply the remaining CIS-liable amount by the verified rate.
This is general information, not tax, legal or accounting advice.
Worked example
For a £1,000 payment containing £200 of qualifying materials, the CIS-liable amount is £800. At a verified 20% rate, the deduction is £160 and the amount payable is £840 before considering any VAT that must be treated separately. Keep the contractor deduction statement with the invoice and payment record.
Important limitations
The tool does not verify subcontractor status or decide whether work, travel, fuel or materials fall inside CIS. Enter the amount excluding VAT and only qualifying materials supported by the contractor calculation. Gross-payment status, 20% and 30% rates depend on HMRC verification; use the confirmed rate rather than choosing the most favourable result.
Common questions
Does Billoz store my calculator entries?
No. These public calculations run in the browser and are not saved to a Billoz account.
Is the result professional advice?
No. It is an indicative calculation based on the values entered and the displayed method.
Should I keep a record of the calculation?
For an important decision, retain the inputs, result, source and calculation date with the relevant invoice or business record.