CIS deduction calculator
Enter the labour and materials on your invoice. The deduction is applied to labour only, which is how the Construction Industry Scheme works — materials, plant hire and fuel are excluded.
Materials, plant hire and fuel are excluded from the deduction. VAT is calculated separately and is never subject to CIS. The deduction is credited against your Income Tax and National Insurance.
How the calculation works
The contractor deducts a percentage of your labour charge and pays it to HMRC against your tax bill. Materials are never included in that calculation, and neither is VAT.
- Start with the labour element of your invoice
- Multiply it by your CIS rate — 20% if registered, 30% if not, 0% with gross payment status
- That figure is the deduction the contractor withholds
- You are paid the invoice total minus the deduction
- The deduction is credited against your Income Tax and National Insurance when you file
The deduction is not a cost. It is your own tax paid early. But it does hit your cash flow this month, which is why it needs to be planned for on CIS-heavy work.
For the full picture — who deducts, when it applies and how to move off the 30% rate — read the guide to CIS deductions.
Calculator questions
Is CIS calculated on materials?
No. The deduction applies to the labour element only. Materials, plant hire, equipment hire and fuel are excluded.
Which CIS rate should I use?
20% if you are registered with HMRC under CIS, 30% if you are unregistered or unverified, and 0% if you have gross payment status.
Does VAT affect the CIS deduction?
No. VAT is calculated separately and is never subject to the CIS deduction.
Is this calculator free?
Yes, completely free with no signup. It runs in your browser and nothing you type is sent anywhere.
Or let your invoicing app do it
Quill splits labour from materials as you write the invoice and applies your CIS rate automatically, so the net figure is right before you send it.