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

What is a UTR number?

A Unique Taxpayer Reference (UTR) is a ten-digit number HMRC uses to identify you — or your limited company — within the Self Assessment and Corporation Tax systems. Every person who registers for Self Assessment is issued their own UTR, and every limited company is issued a separate UTR for Corporation Tax when it is incorporated.

You will use your UTR every time you file a Self Assessment tax return, make a payment to HMRC relating to Self Assessment, or communicate with HMRC about your tax affairs. It stays the same for life once issued — it does not change if you stop and later restart self-employment.

Who needs a UTR?

You need a UTR if you:

• Are self-employed as a sole trader
• Are a partner in a business partnership
• Are a director of a limited company (for your own Self Assessment, separate from the company's UTR)
• Have income that needs to be reported through Self Assessment — for example, significant rental income, or income over certain thresholds from savings, investments, or dividends
• Need to file a return for any other reason HMRC has asked you to

If you registered as self-employed, see our step-by-step guide to registering with HMRC — a UTR is issued automatically as part of that process.

How to get a UTR number

You cannot apply for a UTR on its own — it is issued automatically once you register for Self Assessment (as a sole trader or individual) or once you incorporate a limited company (as a Corporation Tax UTR). The steps are:

1. Register for Self Assessment online at gov.uk, or set up a limited company through Companies House
2. HMRC processes the registration
3. HMRC posts your UTR to your registered address, usually within about 10 working days for a UK address, and this can take longer if you are registering from abroad

Because it is sent by post rather than shown online immediately, it is worth registering with plenty of time before you need to file a return or make a payment — not the week before a deadline.

Where to find your UTR if you already have one

If you have registered before and cannot find the original letter, your UTR appears on:

• Previous Self Assessment tax returns or statements
• Payment reminders or "Notice to complete a tax return" letters from HMRC
• Your Personal Tax Account on gov.uk
• The HMRC app, once you have signed in

If none of these are available, you can contact HMRC's Self Assessment helpline, and they will verify your identity before confirming or reissuing the number by post — HMRC will not read out a UTR over the phone to an unverified caller, for security reasons.

UTR vs National Insurance number vs company number

These three are easy to confuse but serve different purposes:

A sole trader will typically only ever deal with a UTR and a National Insurance number. A limited company director deals with all three: their own personal UTR, the company's separate UTR, and the company registration number.

What if you lose your UTR or never receive it?

If it has been more than a few weeks since you registered and you have not received your UTR letter, contact HMRC directly rather than registering again — submitting a second registration can create confusion and delay matters further. Keep a note of your UTR somewhere secure once you receive it, alongside your Government Gateway login details, since you will need both every year at filing time.

Getting your UTR sorted early — and keeping it somewhere safe — removes one more thing to scramble for when your Self Assessment deadline approaches.