Who should register for CIS?
A business carrying out construction work for a contractor as a subcontractor should consider CIS registration.
CIS can apply to sole traders, partnerships and companies carrying out qualifying construction operations in the UK.
When should a subcontractor register?
HMRC's CIS340 guidance says a subcontractor should register when they, their firm or their company are about to start work within the construction industry.
A subcontractor who is not appropriately registered and matched can normally face the higher CIS deduction rate rather than the standard registered rate.
What information do you need to register?
- Your legal business name.
- Your trading name if different.
- Your business UTR.
- Your trading start date.
- Your VAT registration number if VAT registered.
- Your National Insurance number where relevant.
- Partnership or company details where applicable.
Why do you need a UTR?
Your Unique Taxpayer Reference helps HMRC identify your tax record and is used as part of CIS registration and contractor verification.
See our CIS UTR Number Guide.
Can CIS registration be completed online?
Yes. HMRC describes online registration as the quickest method and says the standard online process registers a subcontractor for net payment status.
What if you have just become self-employed?
If you do not yet have a UTR, register as a new business for Self Assessment and select that you are working as a subcontractor when prompted.
Self Assessment + CIS can be registered together
This avoids trying to complete standard CIS registration before HMRC has created your Self Assessment business record.
What if you are both a contractor and subcontractor?
Some construction businesses receive payments as subcontractors but also pay other subcontractors themselves.
HMRC says a business in that situation needs to follow both sides of the CIS rules and register appropriately as both.
Do overseas subcontractors register?
A business based outside the UK can still need to register for CIS where it carries out construction work in the UK.
What happens after registration?
HMRC confirms the registration and provides the information needed when dealing with contractors.
Before making certain payments, the contractor verifies the subcontractor with HMRC. HMRC then tells the contractor which tax treatment applies.
What deduction rate applies after registration?
| Status | General CIS treatment |
|---|---|
| Registered and verified | Normally standard 20% deduction where paid under deduction. |
| Not appropriately registered or unmatched | Higher 30% deduction can apply. |
| Gross payment status | Contractor pays without CIS deduction. |
Does registering automatically give gross payment status?
Standard registration normally gives net payment status. Gross payment status has separate HMRC qualifying conditions and application requirements.
Reviewed & Updated
18 August 2026
CIS registration
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HMRC CIS340
CIS Registration FAQs
Do I need a UTR before registering?
The normal CIS registration service uses a UTR. New sole traders without one can register for Self Assessment and CIS together.
Does CIS registration make me self-employed?
No. Employment status is determined from the particular working arrangement.
Will registering reduce 30% CIS to 20%?
A successfully registered and verified subcontractor paid under deduction is normally subject to the standard rate rather than the higher rate.
Do I need to register if I also pay subcontractors?
If you operate as both contractor and subcontractor, HMRC says you need to register for both roles.
Official HMRC Sources
GOV.UK — Register as a CIS subcontractor HMRC — CIS340Need help with CIS registration or tax?
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