CIS Invoices For Subcontractors (Plain English)

Quick Answer

CIS is how many UK construction contractors deduct tax from payments to subcontractors. Your invoice should show who you are, your UTR where needed, labour and materials clearly, and enough detail for the contractor to apply the right deduction rate (often 0%, 20%, or 30%). Keep copies and treat this as process help, not tax advice.

Introduction

If you work for main contractors or larger building firms, you will meet the Construction Industry Scheme sooner or later. Money arrives net of a deduction, statements arrive with codes you barely recognise, and your invoice suddenly needs more than a total and a bank sort code.

Plenty of good trades get paid late or chase unpaid balances because CIS paperwork was incomplete or labour and materials were mixed into one vague line. The scheme is not mysterious once you know what belongs on the document and what the contractor needs to verify you.

This guide is practical admin for UK plumbers, electricians, carpenters, and other trades billing under CIS. It is general information only. Your accountant or HMRC guidance should decide your tax position.

Why CIS Invoices Matter

You get paid correctly. Incomplete invoices give contractors an excuse to hold payment while they chase your UTR, NI number, or a materials split.

Your rate depends on status. Deduction at 20% or 30% versus gross payment changes cash flow every week. Verification and clean records support the rate you should be on.

Materials are treated differently. CIS deductions usually apply to labour elements, not qualifying materials. If you bury everything in one lump sum, you can lose money that should have been paid in full.

Year end is easier. Matching invoices, remittance advice, and job notes saves your accountant hours and reduces surprises when deductions are set against your tax bill.

What CIS Is (In Plain English)

CIS is a HMRC scheme for certain payments in the construction industry. Contractors often deduct a percentage from payments to subcontractors and pay that amount to HMRC on your behalf. You still invoice the full amount. You receive the net after deduction (plus materials treated correctly), and the deduction sits against your tax.

Not every trade payment is CIS. Not every customer is a CIS contractor. Domestic homeowners paying you for a bathroom refit are usually outside this setup. The scheme bites when you supply labour (and sometimes other construction services) to contractors who must operate CIS.

Always confirm with your accountant whether a job sits under CIS before you set invoice templates for that client.

UTR And Verification

Your Unique Taxpayer Reference (UTR) identifies you to HMRC. Contractors verify subcontractors with HMRC so they know which deduction rate to use. If you are not verified, higher deductions are more likely.

Keep your trading name, address, UTR, and National Insurance number ready to share when a new contractor onboards you. Put stable company details on every invoice so their accounts team is not guessing from WhatsApp screenshots.

Verification is the contractor's process with HMRC. Your job is to give accurate details promptly and keep them consistent across invoices and your tax records.

Deduction Rates: 0%, 20%, And 30%

Gross payment (often talked about as 0% deduction). Some subcontractors are registered for gross payment. The contractor may pay without CIS deduction if HMRC confirms that status. You still invoice clearly; the remittance just has no CIS line.

Standard rate (commonly 20%). Many verified subcontractors are paid with 20% deducted from the labour element under CIS rules.

Higher rate (commonly 30%). Often applies when the subcontractor cannot be verified or details are wrong. Cash flow hurts here. Fix verification quickly rather than arguing every remittance.

Rates and rules can change. Check current HMRC CIS guidance or your accountant for your status. Do not invent a rate on the invoice to "make it look right". Show the full charge; the contractor applies the deduction based on verification.

Common Mistakes On CIS Invoices

• One vague line like "Works as discussed £4,500" with no labour and materials split
• Missing UTR, company number, or address the contractor needs for their records
• Treating CIS deduction as VAT (they are separate; see VAT on quotes and invoices)
• Invoicing the net amount only so the contractor cannot match HMRC returns
• No purchase order, job reference, or site address on multi-site contracts
• Materials receipts not kept when you claim materials outside deduction
• Raising invoices from memory weeks later with wrong dates and wrong site
• Assuming every commercial client is CIS without checking

What Belongs On A CIS-Friendly Invoice

Use the same discipline as normal trade invoices, then add CIS clarity. Broader structure sits in How Tradesmen Should Create And Manage Invoices Properly.

1. Your business identity. Legal name, trading name if different, address, contact details, company number if limited.
2. UTR and tax identifiers. Include your UTR where the contractor expects it. Add VAT number if you are VAT registered.
3. Invoice number and date. Sequential numbers help both of you. Date the tax point correctly.
4. Contractor details. Their legal name, address, and any supplier or subcontractor account number they gave you.
5. Job references. Site address, purchase order, and your internal job number.
6. Clear description of work. What you did, where, and when. Enough for a QS or accounts clerk who was never on site.
7. Labour and materials split. Show labour (and other deductible elements as advised) separately from materials you supplied.
8. VAT treatment. Net, VAT, and gross if registered. CIS is not a substitute for VAT lines.
9. Payment details. Bank account for the net payment they will send.
10. Gross total before CIS deduction. Invoice the amount due before the contractor deducts CIS. Their remittance shows the deduction.

If you need a quick sense-check on VAT figures around the same invoice, use the VAT calculator.

Labour Vs Materials

Contractors generally deduct CIS from labour (and certain other construction payments), not from qualifying materials you bought and supplied. That is why a clean split matters.

Labour. Your time, day rates, measured works, call-outs, and similar charges for your work on site.

Materials. Goods you purchased and supplied for the job, supported by invoices or delivery notes when asked. Markup rules and what counts as materials can be technical. Ask your accountant how to present materials on your invoices.

Do not inflate "materials" to dodge deduction. That creates bigger problems than a 20% cash-flow hit. Be honest, keep receipts, and show the split clearly.

Simple Checklist Before You Send

1. Confirm the client operates CIS on this work
2. Confirm they have verified you (or know what rate they will use)
3. Split labour and materials on separate lines
4. Add UTR and matching business details
5. Add site, PO, and job reference
6. Show VAT correctly if registered
7. Invoice the gross amount before CIS deduction
8. Save PDF and attach any materials evidence the contractor asked for
9. File the remittance when payment arrives and check the deduction matches expectations

Keep Records With The Job

CIS arguments often start months later. Someone asks which week the labour was for, or which site the materials belonged to. If the answer lives in a buried email thread, you lose time.

Keep for each job: the quote or order, your invoice, materials receipts, contractor remittance, and any verification emails. Align that habit with day-to-day job control in How To Manage Jobs For A Small Trades Business.

When payment is slow after a clean CIS invoice, cash collection habits in How To Get Paid Faster As A Tradesman still apply. CIS does not excuse endless silence from accounts payable.

How Software Helps

Paper and spreadsheets make CIS messy because UTR, site references, and materials lines get reinvented on every invoice. Job software helps when CIS details sit with the same job as the quote, timesheets, and materials notes.

Total Tradesmen keeps one job record from enquiry through to invoice. You can carry labour and materials lines from the work you logged, keep contractor references on the job, and raise invoices that match what happened on site. Van and office are not rebuilding CIS paperwork from memory on Friday night.

If you are still deciding whether software beats ad hoc admin, read Job Management Software Vs Spreadsheets and How To Choose Job Management Software For UK Trades. Compare tools on the alternatives hub.

Benefits Of Clean CIS Invoicing

• Faster payment because accounts have what they need first time
• Less money wrongly deducted from materials that should have been paid gross
• Clearer remittance checks each month
• Easier conversations with your accountant at year end
• Fewer disputes about what work was done on which site

FAQs

Should my invoice show the CIS deduction?

Usually you invoice the full charge for the work and materials as agreed. The contractor applies the CIS deduction on payment and shows it on their statement. Follow what that contractor's accounts team asks for, and check with your accountant if their template differs.

Is CIS the same as VAT?

No. VAT is a tax on taxable supplies if you are registered. CIS is a deduction scheme on certain construction payments. Show them separately. See VAT on quotes and invoices for tradesmen.

Do I need a UTR on every invoice?

Many contractors expect it. Even when not printed, they need your UTR for verification. Putting it on the invoice reduces back-and-forth.

What if they deduct 30%?

Check whether you are unverified or details were wrong. Fix verification with the contractor and HMRC processes promptly. Ask your accountant how the higher deduction affects your cash and tax position.

Can I invoice a limited company and a sole trader the same way?

Layout can be similar, but the legal name, UTR, and company number must match who is actually contracting. Do not mix personal and company identities on the same paperwork.

Is this tax advice?

No. This is practical invoicing guidance for UK trades. CIS rules, rates, and your registration status must be confirmed with HMRC guidance or a qualified accountant.

Working With Contractors Day To Day

Agree upfront how they want materials evidenced, what PO format they need, and whether they use application for payment processes before the final invoice. Large sites often reject tidy invoices that skip their internal steps.

Send invoices on a fixed rhythm, weekly or per valuation, rather than one giant bill at the end. Smaller documents are easier to match to CIS returns and site diaries.

When a remittance arrives, tick off invoice numbers the same day. Query wrong rates within the month, not six months later when the QS has moved on.

CIS And Your Wider Admin

CIS sits beside quoting, scheduling, and ordinary invoicing. Quote clearly so labour allowances are not a surprise. Log time and materials on the job so the CIS invoice is not fiction. Get paid follow-up still matters when net payment is late.

Link your habits across quoting, invoicing, and getting paid faster so CIS work does not become a separate messy silo.

Disclaimer

Nothing on this page is tax, legal, or accounting advice. CIS rules, deduction rates, gross payment status, and what counts as materials depend on your facts and current HMRC rules. Speak to your accountant or tax adviser before you change how you invoice or claim status.

Conclusion

CIS invoices work when they are complete, split labour and materials clearly, and match the job that was actually done. Know your UTR and verification status, invoice the gross amount properly, keep remittances with the job, and ask an accountant when something looks unusual. Clean paperwork gets you paid sooner and makes year end far less painful.