CIS registration for contractors: step-by-step UK guide
If your UK company pays subcontractors for construction work, you may need to register under the Construction Industry Scheme (CIS) before the first payment, not after HMRC writes.
CIS is separate from PAYE, VAT, and corporation tax. It is its own monthly compliance rhythm.
What is CIS registration?
CIS registration is HMRC's process for contractors who pay subcontractors for construction-related work to register, verify subcontractors, deduct tax at source, and file monthly CIS returns.
Registration is for the contractor (the company paying). Subcontractors also register and seek verification for reduced deduction rates.
CIS registration steps at a glance
SYSTEM INSIGHT / NEXT STEP
Make the next move with clarity.
If this issue is already showing up in reporting, runway, or team decisions, the next move is usually clearer with a structured finance view.
Step 1: Confirm CIS applies to your business
CIS covers construction operations and certain related services. Check if your payments qualify before registering.
UK startups that sometimes miss CIS:
Proptech companies managing refurbishments
Facilities businesses hiring trade subcontractors
Hardware or installation teams using external fit-out firms
If unsure, ask your accountant before the first subcontract invoice is paid.
Step 2: Register as a contractor with HMRC
Register online for CIS as a contractor if you pay subcontractors for qualifying work. You will need:
Company UTR
Companies House details
Nature of work you subcontract
Allow time before first payment. Retroactive CIS mistakes are painful to unwind.
Step 3: Verify each subcontractor
Before paying a subcontractor, verify them with HMRC to confirm deduction status:
Status | Typical deduction |
Verified, registered sub | 20% |
Unverified or higher rate | 30% |
Keep verification records. Subcontractors often challenge unexpected 30% deductions.
Step 4: Deduct CIS on qualifying payments
Deduct CIS from labour element of payments (not materials where rules allow separation). Record:
Gross payment
Materials (if excluded)
CIS deducted
Net paid to subcontractor
Tag CIS payments clearly in Xero for monthly return prep.
Step 5: File monthly CIS returns
Submit your CIS return by the 19th of each month for the previous tax month (6th to 5th). See our CIS monthly return deadline guide.
File nil returns even if you made no payments that month.
Step 6: Issue payment statements
Provide subcontractors with statements showing deductions. Good process reduces disputes and supports their Self Assessment.
CIS registration mistakes founders make
Paying before registration. Register before first qualifying payment where possible.
Treating all invoices as materials. HMRC rules on labour vs materials are specific. Split lines correctly.
Ignoring CIS because you are a tech company. Physical works and subcontractor spend can still trigger CIS.
Missing nil returns. A quiet month still needs a return by the 19th.
FAQs
Who must register for CIS as a contractor?
UK businesses that pay subcontractors for construction operations or certain related services must register as contractors under CIS.
How do I register for CIS with HMRC?
Register through HMRC's CIS online service as a contractor. You need your company tax references and details of your business activity.
What is the difference between CIS contractor and subcontractor registration?
Contractors pay subcontractors and deduct CIS. Subcontractors receive payments and may register to be verified for a lower deduction rate.
How long does CIS registration take?
Allow several working days before you need to pay subcontractors. Do not leave registration until invoice due date.
Is CIS linked to VAT registration?
No. CIS is separate. You may need both depending on your business.
**Paying subcontractors and need CIS set up correctly?** Talk to an Expert.
