Tax30 May 2026 · 3 min read

What Is a UTR Number and How Do You Get One?

If you've recently gone self-employed or started working as a subcontractor under CIS, someone's probably asked for your UTR number. Here's exactly what it is, why you need it, and how to get one.

What is a UTR number?

UTR stands for Unique Taxpayer Reference. It's a 10-digit number that HMRC uses to identify you for Self Assessment and CIS purposes. Think of it as your tax ID number for self-employment.

Every self-employed person in the UK has one. It stays with you for life — it doesn't change if you move, change trade, or stop and restart self-employment.

Why do you need it?

You need your UTR to: File a Self Assessment tax return Register for CIS as a subcontractor Give to contractors so they can verify your CIS status Work with an accountant on your tax affairs

Without a UTR, you can't be verified under CIS. That means any contractor you work for has no choice but to deduct at 30% — the unregistered rate — regardless of whether you're otherwise compliant.

How do you get a UTR number? You get a UTR by registering for Self Assessment with HMRC. You do this at gov.uk/register-for-self-assessment.

The process: Go to gov.uk and search for "register for Self Assessment" Select the option for self-employed Create a Government Gateway account if you don't have one Complete the registration form — you'll need your National Insurance number, date of birth, address and the date you started self-employment HMRC will send your UTR to your home address by post — this takes up to 10 working days

Once you receive your UTR letter, keep it somewhere safe. You'll need the number repeatedly.

Can you get a UTR number faster?

The letter takes up to 10 days. You can also call HMRC directly on 0300 200 3310 and ask for your UTR — if you've already registered online, they may be able to give it to you over the phone before the letter arrives.

If you're in a genuine hurry because a contractor needs it before your next payment, explain the situation. HMRC are usually helpful in these circumstances.

What if you've lost your UTR?

If you had a UTR previously but can't find it: Check old Self Assessment letters or tax returns Log in to your HMRC online account — it's listed there Call HMRC on 0300 200 3310 and ask — they can confirm it after security questions

Don't make up or guess a UTR number. Giving a contractor a wrong number means they can't verify you and will deduct at 30%.

When should you register? As soon as you start self-employment — or ideally before. HMRC require you to register by 5 October following the end of the tax year in which you started working for yourself. But because getting a UTR takes up to 10 days, and because you need it for CIS, register the moment you decide to go self-employed.

Is a UTR number the same as a CIS number?

Not exactly. Your UTR is used to identify you within CIS, but CIS registration is a separate step. Once you have your UTR, you register for CIS specifically through your Government Gateway account or by calling the CIS helpline on 0300 200 3210.

The UTR comes first. CIS registration follows.

What happens after you register?

Once you have your UTR and are CIS registered, contractors can verify you online before making payments. Verification confirms your name, UTR and the correct deduction rate (20% if registered, 0% if you have Gross Payment Status). The contractor keeps a record of the verification reference for each payment.

Keep your UTR number somewhere accessible — you'll use it every time you deal with HMRC, your accountant, or a new contractor.

Related guides: How to Register as Self-Employed · How to Register for CIS · Self Assessment for Tradespeople

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