Is my CIS number the same as my UTR?

In practice, yes. As of October 2026, GOV.UK describes no separate CIS number for subcontractors: contractors verify you using your 10-digit Unique Taxpayer Reference (UTR), your National Insurance number and your registered name.

The Construction Industry Scheme (CIS) does have numbers of its own, but they belong to the contractor or to the check the contractor makes, not to you. This guide sets out which is which, using GOV.UK's CIS guidance, HMRC's CIS 340 guide and HMRC's CIS manual, all checked on 17 October 2026. It only gives formats that GOV.UK or HMRC state or show.

The numbers in CIS and whose they are

Why people talk about a "CIS number"

The idea comes from the old scheme. HMRC's CIS glossary describes the CIS4 registration card, which confirmed a subcontractor was registered under the scheme that ran from 1 August 1999 until 5 April 2007. Since then there has been no card.

Today, GOV.UK says you need a UTR to register online, and that if you have none you can register as a new business for Self Assessment, choose "working as a subcontractor" and be registered for both at once. CIS 340 says HMRC then writes to confirm your registration and tells you what to give your contractors. GOV.UK says that when you start with a contractor you give the exact details you registered with, including your UTR and your legal business or trading name. HMRC's manual says the contractor sends your UTR, National Insurance number and name, and HMRC's system looks for your CIS record using them.

So when a contractor or agency asks for your "CIS number", give them your UTR, your National Insurance number and the name you registered with, spelt the same way.

What the contractor gets back

When a contractor verifies you, HMRC gives it a verification reference. CIS 340 explains how it works:

• Everyone the contractor verifies at the same time shares one reference, so it is not personal to you.
• If HMRC cannot verify you, it adds one or two letters to the end so the reference is unique to you, and the contractor must deduct 30% instead of 20%.
• The contractor must show that reference, letters and all, on the monthly return and on your payment and deduction statement whenever 30% is taken. It does not need to show it when you are paid at 20% or gross.

So a verification number on your statement is a warning sign. CIS 340 says you need it later to get credit for those deductions, so keep the statement.

The contractor's references on your statement

CIS 340 says each statement must show the contractor's name and employer tax reference, then your name and UTR. The employer reference is the contractor's: GOV.UK says contractors register through HMRC's new-employer process and get a letter with their employer PAYE reference. The accounts office reference, 13 characters long, is what the contractor quotes when it pays HMRC. Neither is yours to give anyone else.

If you also pay subcontractors yourself, you get these two references for your own contractor scheme. Your UTR stays the same.

What this means for you

You need one number to get the 20% rate: your UTR, matched with your National Insurance number and registered name. A wrong digit or a different spelling can mean HMRC cannot match you, and 30% is taken until the details are put right. The extra deduction is not lost, because it counts towards your tax for the year, but you wait until after the tax year to get any overpayment back.

Steps to give contractors the right details

1. Find your UTR. GOV.UK lists your personal tax account, the HMRC app, previous tax returns and HMRC letters such as notices to file or payment reminders.
2. Have your permanent National Insurance number to hand. Temporary numbers cannot be verified.
3. Use the exact legal name, or the one trading name, you gave when you registered for CIS.
4. Give all three to each new contractor before your first payment, so it can verify you.
5. When the first statement arrives, check your name, your UTR and a 20% rate, and look for any verification number with a letter on the end.

If you have no UTR yet, start with what a UTR is and where to find it. If a statement shows a letter on the end of the verification number, read what unmatched means. If you pay subcontractors yourself, read how to verify a CIS subcontractor. The free MTD check shows when Making Tax Digital starts for you, and the trades section has more on CIS.