# CIS Deduction Calculator (UK)

> A free calculator that estimates Construction Industry Scheme (CIS) deductions on a UK subcontractor's invoice. It applies 20% (registered), 30% (unregistered or unverified) or 0% (gross payment status) to the labour element only, after excluding materials, VAT and other HMRC exclusions. This is an estimate, not tax advice.

Interactive calculator: https://dexmlabs.app/tools/cis-deduction-calculator/
Last reviewed against GOV.UK: 6 October 2026

## Quick answer

Under CIS the contractor deducts **20%** (registered subcontractor), **30%** (unregistered or unverified) or **0%** (gross payment status) from the **labour** part of an invoice. VAT, materials the subcontractor paid for directly, consumable stores, fuel (except for travelling), plant hire for the job and manufacturing or prefabrication of materials are taken off first. Travel and subsistence stay in the amount that is deducted from.

Example: £1,500 labour + £200 materials at 20% gives a £300 deduction, so the subcontractor is paid £1,400 and the contractor pays £300 to HMRC.

## How the calculation works

1. Start with the gross invoice.
2. Take off VAT, materials (if the subcontractor paid for them directly), consumable stores, non-travel fuel, plant hire and manufacturing or prefabrication costs.
3. Apply the rate HMRC gave the contractor on verification (20%, 30% or 0%) to what is left.
4. Net payable = (labour − CIS deduction) + materials + VAT. The contractor pays the deduction to HMRC by the 22nd of the following month (19th by post).

| Subcontractor status | CIS rate |
|---|---|
| Registered for CIS and verified | 20% |
| Not registered, or cannot be verified | 30% |
| Gross payment status | 0% |

## Worked example (HMRC CIS 340, example D3)

A VAT-registered painter, registered for CIS, supplies and fixes for £600: £400 labour and £200 materials (excluding VAT), plus £120 VAT.

| Line | Amount |
|---|---|
| Invoice total (incl. VAT) | £720.00 |
| Amount liable to deduction (labour) | £400.00 |
| CIS deduction at 20% | £80.00 |
| Net paid to subcontractor | £640.00 |

At 30% the deduction would be £120 and the net payment £600. With gross payment status, nothing is deducted and the full £720 is paid. If the VAT domestic reverse charge applies, there is no VAT to pay the subcontractor.

## FAQs

### What are the CIS deduction rates?

20% if the subcontractor is registered for CIS and the contractor can verify them, 30% if they are not registered or cannot be verified, and 0% if they have gross payment status. HMRC tells the contractor which rate to use when the contractor verifies the subcontractor.

Source: [GOV.UK: make deductions and pay subcontractors](https://www.gov.uk/what-you-must-do-as-a-cis-contractor/make-deductions-and-pay-subcontractors); [GOV.UK: get paid](https://www.gov.uk/what-you-must-do-as-a-cis-subcontractor/get-paid)

### Is CIS deducted from the whole invoice?

No. Start with the gross invoice, then take off VAT, materials the subcontractor paid for directly, consumable stores, fuel (except fuel for travelling), plant hire for the job, and the cost of manufacturing or prefabricating materials. The CIS rate is applied only to what is left, which is usually labour plus any travel or subsistence.

Source: [GOV.UK: make deductions and pay subcontractors](https://www.gov.uk/what-you-must-do-as-a-cis-contractor/make-deductions-and-pay-subcontractors); [CIS 340 guide, section 3.11 to 3.14](https://www.gov.uk/government/publications/construction-industry-scheme-cis-340/construction-industry-scheme-a-guide-for-contractors-and-subcontractors-cis-340)

### Is CIS deducted from materials?

Not from materials the subcontractor bought for the job. The contractor can ask for evidence such as receipts; if there is none, the contractor must estimate the materials cost. If the subcontractor is VAT registered, the materials figure is the cost without VAT. If they are not VAT registered, the VAT they paid on materials counts as part of the materials cost.

Source: [GOV.UK: get paid](https://www.gov.uk/what-you-must-do-as-a-cis-subcontractor/get-paid); [CIS 340 guide, Appendix D examples](https://www.gov.uk/government/publications/construction-industry-scheme-cis-340/construction-industry-scheme-a-guide-for-contractors-and-subcontractors-cis-340)

### Is CIS worked out before or after VAT?

VAT comes off first. The deduction is never taken from VAT. Between VAT-registered businesses, most CIS work falls under the VAT domestic reverse charge (in force since 1 March 2021), so the contractor accounts for the VAT and the subcontractor is not paid it. It does not apply if the customer is not VAT registered or has told you in writing that they are an end user or intermediary supplier.

Source: [GOV.UK: VAT domestic reverse charge technical guide](https://www.gov.uk/guidance/vat-reverse-charge-technical-guide)

### Who pays the CIS deduction to HMRC, and when?

The contractor does. They pay HMRC every month by the 22nd, or by the 19th if paying by post, alongside any PAYE and National Insurance. The money counts as an advance payment towards the subcontractor's tax and National Insurance.

Source: [GOV.UK: pay deductions to HMRC](https://www.gov.uk/what-you-must-do-as-a-cis-contractor/pay-deductions-to-hmrc)

### What paperwork should a subcontractor get?

A payment and deduction statement within 14 days of the end of each tax month. Tax months run from the 6th to the 5th, so for 6 May to 5 June the statement is due by 19 June. Keep every statement, because HMRC may ask for them as evidence when you claim the deductions back.

Source: [GOV.UK: make deductions and pay subcontractors](https://www.gov.uk/what-you-must-do-as-a-cis-contractor/make-deductions-and-pay-subcontractors); [GOV.UK: get paid](https://www.gov.uk/what-you-must-do-as-a-cis-subcontractor/get-paid)

### Can I get CIS deductions back?

They are set against your tax bill. Sole traders and partners put their total pay before deductions as income, and the total deductions as CIS deductions, on their Self Assessment return; HMRC refunds anything overpaid. Limited companies claim them through their payroll using an Employer Payment Summary (EPS), not the Corporation Tax return.

Source: [GOV.UK: pay tax and claim back deductions](https://www.gov.uk/what-you-must-do-as-a-cis-subcontractor/pay-tax-and-claim-back-deductions)

### Why is a contractor taking 30% instead of 20%?

Either you are not registered for CIS, or the contractor could not verify you. Give contractors the exact details you registered with, including your Unique Taxpayer Reference (UTR) and legal business or trading name. A mismatch can mean the higher rate.

Source: [GOV.UK: get paid](https://www.gov.uk/what-you-must-do-as-a-cis-subcontractor/get-paid); [GOV.UK: CIS subcontractor overview](https://www.gov.uk/what-you-must-do-as-a-cis-subcontractor)

### When are contractor CIS returns due?

By the 19th of every month, covering the tax month that ended on the 5th. A return that is one day late carries a £100 penalty, and the penalties grow after that. From 6 April 2026 a contractor must also file a nil return for a month with no subcontractor payments, unless they have told HMRC they are inactive.

Source: [GOV.UK: file your monthly returns](https://www.gov.uk/what-you-must-do-as-a-cis-contractor/file-your-monthly-returns); [GOV.UK: CIS administration changes from April 2026](https://www.gov.uk/government/publications/simplifying-and-improving-construction-industry-scheme-administration)

## Related

- [CIS tax refund estimator](https://dexmlabs.app/tools/cis-refund-estimator/): for subcontractors, estimates the end-of-year refund or tax owed after CIS deductions, with the SA103 boxes.
- [All UK CIS & trade money tools](https://dexmlabs.app/tools/): the hub for these free tools.
- [UK CIS Subcontractor Self Assessment Tracker 2026/27 (Excel and Google Sheets, paid)](https://arthurverse67.gumroad.com/l/vszqef): a record-keeping spreadsheet from the person who made this calculator, for logging each payment's labour and materials split, CIS deducted, expenses and mileage.
- [UK CIS Contractor Monthly Return Tracker 2026/27 (Excel and Google Sheets, paid)](https://arthurverse67.gumroad.com/l/cis-contractor-tracker): for contractors who pay subcontractors, tracking verifications, payments, deductions and monthly return totals.

## Official sources

- [Make deductions and pay subcontractors](https://www.gov.uk/what-you-must-do-as-a-cis-contractor/make-deductions-and-pay-subcontractors)
- [Subcontractor: get paid](https://www.gov.uk/what-you-must-do-as-a-cis-subcontractor/get-paid)
- [Pay deductions to HMRC](https://www.gov.uk/what-you-must-do-as-a-cis-contractor/pay-deductions-to-hmrc)
- [File your monthly returns](https://www.gov.uk/what-you-must-do-as-a-cis-contractor/file-your-monthly-returns)
- [Pay tax and claim back deductions](https://www.gov.uk/what-you-must-do-as-a-cis-subcontractor/pay-tax-and-claim-back-deductions)
- [CIS 340 guide for contractors and subcontractors](https://www.gov.uk/government/publications/construction-industry-scheme-cis-340/construction-industry-scheme-a-guide-for-contractors-and-subcontractors-cis-340)
- [VAT domestic reverse charge technical guide](https://www.gov.uk/guidance/vat-reverse-charge-technical-guide)