Last checked October 2026 · by the PaySorted team
Who should register
You should register as a CIS subcontractor if you do construction work for a contractor and you're a sole trader, a partner in a partnership, or the owner of a limited company. It isn't compulsory, but if you don't, the contractor must deduct 30%.
You don't register if you're an employee. If you also pay subcontractors yourself, you must register as a contractor too.
What gets deducted
| Your status | Deduction from labour |
|---|---|
| Registered for CIS | 20% |
| Not registered | 30% |
| Gross payment status | 0% |
Deductions come off the labour only — not materials you bought, VAT, or plant hire. See how to show CIS on an invoice, or try the CIS calculator.
What you need
- your legal name and any trading name
- your UTR (Unique Taxpayer Reference)
- your National Insurance number
- your VAT number, if you're VAT registered
- the date you started trading
- for a company: the company registration number
No UTR yet? Register as self-employed for Self Assessment and choose "working as a subcontractor". That registers you for Self Assessment and CIS at the same time.
How to register, step by step
- Go to gov.uk and search "register as a CIS subcontractor".
- Sign in with your HMRC online services (Government Gateway) account, or create one.
- Enter your details and choose to register for net payment status (20%).
- Give your contractor the same name and UTR you registered with. They'll "verify" you with HMRC before paying you, and HMRC tells them which rate to use.
You can also register by post using the form for your business type. You can't register by phone — the CIS helpline (0300 200 3210) is for questions only.
Monthly statements
Each month, the contractor must give you a payment and deduction statement within 14 days of the end of the tax month (tax months end on the 5th). It shows what you were paid and what was deducted. Keep every one — they're your proof when you claim the money back.
If a contractor won't give you your statements, you can write to HMRC (PT Operations, HM Revenue and Customs, BX9 1BX) with your details, theirs, and the dates involved.
Getting your deductions back
Sole traders and partners: on your Self Assessment return, put your total pay before deductions as income, and the CIS deductions separately. HMRC takes them off your tax and National Insurance bill and repays anything you've overpaid. Many subcontractors get a refund, so filing early pays.
Limited companies: claim through the company's PAYE scheme each month on the Employer Payment Summary (EPS), not on the Corporation Tax return.
In PaySorted, turn on CIS once and every invoice splits labour and materials, takes off the right rate, and keeps a running total of deductions for your tax return.
General information based on HMRC guidance (checked October 2026), not tax advice.
Common questions
How long does it take to register for CIS?
Registering online only takes a few minutes if you have your UTR and Government Gateway login ready.
Can I register for CIS over the phone?
No. HMRC says subcontractors can't register by phone. Register online or by post.
What happens if I don't register for CIS?
The contractor must deduct 30% from your labour instead of 20%. You can still claim it back on your tax return, but you wait longer for your money.
Do I need a UTR to register for CIS?
Yes. If you don't have one, register for Self Assessment as a new business and choose "working as a subcontractor" to do both at once.