Free tool · 2026/27 tax year

CIS calculator

Put in the labour and the materials. See what the contractor holds back, what goes to HMRC, and what actually lands in your bank.

20% · 30% · grossLabour only — never materialsVAT reverse charge lineRough rebate estimate

One invoice

Everything before VAT. Nothing you type leaves this page.
Your CIS status
VAT

What you get

Lands in your bank
£0.00
Labour£0.00
Materials£0.00
Invoice before VAT£0.00
VAT£0.00
CIS deduction−£0.00
Paid to you£0.00
Contractor sends HMRCin your name — it counts as tax you've already paid£0.00

    

  


  
  

    

      
The whole year — refund or bill?

      
A rough check for a sole trader, 6 April 2026 to 5 April 2027. England, Wales and Northern Ireland bands.

      
Fill from the invoice above ×
         a year
        
      

      
      
      
    

    

      
Roughly

      
Refund or bill
—
Fill in the year on the left.

      

        
Profitinvoiced less costs£0.00

        
Income tax£0.00

        
Class 4 National Insurance£0.00

        
Owed for the year£0.00

        
Already paid through CIS−£0.00

        
Difference£0.00

      

      
An estimate, not advice: it assumes this is your only income, ignores student loans, payments on account, pension relief and Scottish bands. Your accountant's figure is the one that counts.

    

  







  

    
The Construction Industry Scheme is simple once you see the order things happen in: materials come off first, the percentage is taken from what's left, and VAT sits outside the whole thing. Most wrong invoices get one of those three back to front.


    
1. How the deduction is worked out

    
The contractor paying you takes the invoice before VAT, takes off what you actually paid for materials, and applies your CIS rate to the rest. That amount goes to HMRC in your name; you get the remainder.

    

      
Example — registered, 20%£

      
Labour1,000.00

      
Materials you paid for200.00

      
Invoice before VAT1,200.00

      
CIS deduction — 20% of the £1,000 labour only−200.00

      
Paid to you1,000.00

    

    
The rates: 20% if you're registered for CIS and the contractor has verified you · 30% if you're not registered or HMRC can't match you · 0% if you hold gross payment status. Registering is free and takes one phone call or a few minutes online — a 30% deduction is almost always a registration problem, not a tax one.


    
2. What comes off before the percentage

    
CIS is a deduction from labour. These are taken off the invoice first, at what they cost you:

    
    
      
  • Materials you bought for the job
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  • Consumables — fixings, blades, sealant, fuel for plant
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  • Plant and scaffold you hired in for the job
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  • Manufacturing or prefabricating materials off site
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These do not come off — the percentage is taken from them like any other labour: travel, fuel for getting to site, digs and subsistence. The contractor can ask to see receipts for materials, so invoice what you paid and keep the merchant's ticket. If you're VAT registered, use the materials cost without VAT.


    
3. CIS and VAT — the reverse charge

    
CIS is always worked out on the figure before VAT, and VAT is never reduced by it. Since March 2021 most subbie-to-contractor work falls under the domestic reverse charge: when you and the contractor are both VAT registered and the work is reported under CIS, you charge no VAT at all. The invoice shows the VAT rate and says "Reverse charge: customer to account for the VAT to HMRC", and the contractor deals with it on their own return.

    
You add 20% VAT in the normal way only when the customer is the end user (a homeowner, or a developer who has told you in writing they're an end user) or the work isn't under CIS. If you're not VAT registered, none of this touches you.


    
4. Getting it back

    
The deduction isn't a fee — it's income tax and National Insurance paid early. Sole traders and partners enter the year's deductions on the Self Assessment return; if they come to more than the tax and Class 4 NI you owe, HMRC refunds the difference. Because the 20% is taken from labour before your expenses and before your £12,570 personal allowance, a lot of subbies are owed money every year. Limited companies don't wait for year end: deductions are set against the company's PAYE bill each month through payroll, and any balance is reclaimed from HMRC.

    
Either way you need the paperwork. The contractor must give you a payment and deduction statement for every tax month (the 6th to the 5th) within 14 days of it ending. No statement, no proof — chase them as they fall due, not the following January.


    
5. Quick answers

    
Is CIS deducted from materials?

    
No — labour only. Materials come off the invoice at cost before the percentage is applied.

    
Is CIS worked out before or after VAT?

    
Before. VAT, where it's charged at all, is added on top and paid in full.

    
Why have I had 30% taken?

    
The contractor couldn't verify you with HMRC — usually you're not registered for CIS, or the name, UTR or National Insurance number they hold doesn't match. Get it fixed and the rate drops to 20% from the next payment; the extra already taken comes back through your tax return.

    
Does retention change the deduction?

    
CIS is taken when you're paid, not when you invoice. If 5% is held back, the deduction on that 5% happens when the retention is finally released.

    
When is the money due to HMRC?

    
That's the contractor's job: by the 22nd of each month if they pay electronically (the 19th by post). Your part is keeping the statements.


    

      The rest of the paperwork
      
The calculator does one invoice. ShareDraw does the year.

      
ShareDraw is the site toolkit for subcontractors: every stage claim, day work and extra goes in from the phone with a name on it — and the accountant's workbook comes out the other end.

      
    
        
  • CIS by person and by tax year — UTR, rate, labour → deduction → net
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  • Retention held and released as its own line
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  • Day works signed on site, extras with photo evidence, QA before you claim
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  • £1 per person per week. Every module included.
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        Look around the demo →
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Figures are for the 2026/27 tax year and are a guide only — this page is not tax advice. Rules: HMRC's Construction Industry Scheme guidance (CIS 340). · © Share Draw Limited 2026 · Registered in England & Wales, Company No. 17367750