What Is CIS? A Straightforward Guide to the Construction Industry Scheme
Learn what CIS is, who the Construction Industry Scheme affects, how deductions work, and what contractors need to verify.
CIS is the Construction Industry Scheme. It is a UK tax deduction scheme for construction work under which contractors may need to verify subcontractors and deduct money from certain payments before passing those deductions to HMRC.
Comparison Table
CIS is a payment scheme, not the same thing as employee payroll.
| Topic | Under CIS | Under employee payroll |
|---|---|---|
| Who is being paid? | A subcontractor for construction operations. | An employee or worker paid through payroll. |
| Main process | Verification and possible deduction from payment. | PAYE income tax, NIC, and payroll reporting. |
| Deduction rates | Typically gross, 20%, or 30% depending on verification and status. | Based on tax code, earnings, NIC thresholds, and payroll rules. |
| What the deduction represents | Advance payment towards tax and National Insurance liabilities. | Employment tax withholding through payroll. |
| Core compliance record | Verification, payment statement, and CIS return evidence. | Payslips, RTI submissions, and payroll records. |
Who This Is For
Construction contractors paying subcontractors for construction operations.
Finance teams handling verification, deductions, and returns.
Labour suppliers trying to explain the payment route to clients and subcontractors.
When This Applies
When a contractor pays a subcontractor for construction work covered by the scheme.
When the payer needs to verify the subcontractor and determine whether to pay gross or with deductions.
When the business needs a clean audit trail for CIS returns and payment records.
Detailed Explanation
CIS is about how payments are handled in the construction industry. It does not create every tax rule around labour supply, but it does create a specific process for contractors paying subcontractors for work covered by the scheme.
The contractor usually needs to verify the subcontractor with HMRC. That verification affects whether the payment is made gross, with a 20% deduction, or with a 30% deduction.
HMRC describes the deductions as advance payments towards the subcontractor's tax and National Insurance. That is why the administrative detail matters. If verification, deductions, statements, and returns are handled badly, the commercial issue quickly becomes a tax-control issue.
CIS also matters because it is often treated as a back-office task after onboarding is already complete. In reality, the payment route should be connected to supplier setup, worker record quality, contract structure, and invoice approval from the start.
For operating teams, the strongest CIS process is one where supplier data, verification status, payment instructions, and return evidence all live in the same workflow rather than across spreadsheets and disconnected finance systems.
Frequently Asked Questions
What are the usual CIS payment outcomes?
A subcontractor may be paid gross, with a 20% deduction if registered, or with a 30% deduction if not properly registered or verified. HMRC sets the detailed rules.
Does CIS only matter to large contractors?
No. It matters to any contractor that falls within the scheme and pays subcontractors for covered construction operations.
Are CIS deductions the same as payroll deductions?
No. CIS deductions are part of a construction payment scheme for subcontractors. They are not the same as ordinary PAYE employee payroll processing.
Why do businesses get CIS wrong operationally?
Usually because verification, onboarding, invoice review, and return preparation are handled by different teams without one authoritative record.
Official Sources
This guide is general information, not tax or legal advice. Check the current HMRC and GOV.UK guidance before relying on it for a live engagement.