United Kingdom

CIS deduction calculator

Enter what you invoiced. The deduction is shown at each of the three verification outcomes, with materials and plant hire taken out of the base first.

Your invoice, before VAT

£

What you charged for the work itself.

£

Materials you paid for directly, plus consumable stores and fuel used on the job.

£

Plant hired in for this job, charged on.

£

Manufacturing or prefabricating materials, and equipment charged on.

Invoice total£3,000.00

Filled in with an example invoice so you can see what the page does. Type over it with your own and the address bar carries the answer with it.

What the deduction is taken from

Invoice total
£3,000.00
Taken out before the rate applies
- £600.00
Amount the rate is applied to
£2,400.00

The register describes this base as: the remainder, effectively the labour element.

Deduction at each verification outcome

Verified as registered (20%)

HMRC verified you and you are registered for CIS.

£480.00

You are paid £2,520.00

Not verified or not registered (30%)

The contractor could not verify you, or you are not registered.

£720.00

You are paid £2,280.00

Gross payment status (0%)

HMRC granted you gross payment status, so nothing is withheld.

£0.00

You are paid £3,000.00

What comes off before the rate applies

  • vat
  • materials paid for directly by the subcontractor
  • consumable stores
  • fuel except fuel for travelling
  • plant hire for the job
  • manufacturing or prefabricating materials

Evidence: the contractor may ask for receipts for direct material costs, or estimate if unavailable.

The deduction is your tax paid in advance

It is not a cost and it is not a discount. The contractor pays it to HMRC against your bill, and it is set by HMRC verification, not by agreement between you and the contractor.

Questions this page answers

How much CIS is deducted from a subcontractor invoice?
20% of the labour element when HMRC has verified you as registered, 30% when the contractor could not verify you, and 0% when you hold gross payment status. The percentage is applied to the labour element, never to the invoice total.
Is CIS deducted from materials?
No. Materials, plant hire and other equipment and prefabrication come out of the base before the rate is applied, as long as you actually bore the cost. A deduction taken off the whole invoice is the most common way a subcontractor is short-paid, and it is worth challenging on the invoice rather than at the year end.
What happens if the contractor cannot verify me?
The rate goes to 30% instead of 20%. On a £2,400 labour element that is £240 more withheld from one invoice. Registering for CIS before the payment is made is the whole difference.
Does the deduction come off the VAT as well?
No. CIS is worked out on the invoice before VAT. On most business to business construction work in the UK you do not charge VAT on the invoice at all, because the customer accounts for it under the domestic reverse charge.
Do I get the money back?
It is not a cost, it is tax paid early. What the contractor withholds is paid to HMRC against your own bill, so it comes off your Self Assessment and is refunded if you overpaid. The problem it creates is cash flow, not tax.

Or have the deduction on the invoice before you send it

Build the invoice with materials and plant hire on their own lines and the deduction is computed against the labour element as you type, at whichever verification outcome applies to you. The figure your contractor will withhold is on the document before it leaves, so there is no surprise when the payment lands short.

Reply to an email from the truck and the invoice goes out. There is no monthly charge: a small percentage of each invoice processed, collected on the payment due date.

Open the demo businessRead how to get the deduction back

Where these figures come from

  • cis_deduction_base (GB) Published source Last read from the source 12 Aug 2026.
  • cis_deduction_rate_registered (GB) Published source Last read from the source 12 Aug 2026.
  • cis_deduction_rate_unregistered (GB) Published source Last read from the source 12 Aug 2026.
  • cis_deduction_rate_gross (GB) Published source Last read from the source 12 Aug 2026.

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