Short answer: Your UTR is a 10-digit number that HMRC posts to you about 15 days after you register for Self Assessment. To find a lost one, check your personal tax account, the HMRC app or old HMRC letters, and contact HMRC if you still cannot find it. Limited companies can request their Corporation Tax UTR online.
A Unique Taxpayer Reference (UTR) identifies you to HMRC for Self Assessment. You need it to file a return, set up payments and prove your self-employed status to clients. This guide shows where to look, how to get a new one and what to do when it does not arrive.
What a UTR is
A UTR is a 10-digit number. HMRC sometimes calls it your “tax reference” or “UTR number” on letters and online. It is different from your National Insurance number, and individuals, partnerships and companies each have their own UTR.
Where to find your UTR if you have lost it
- Personal tax account. Sign in to your online tax account on GOV.UK, or use the HMRC app.
- Old HMRC letters. Look for a notice to file a tax return, a payment reminder, a Self Assessment statement or a letter from when you registered.
- Your accountant. If you have one, they have it on file.
- Companies. Check your previous Corporation Tax return or HMRC letters. A limited company can request its Corporation Tax UTR online, and HMRC posts it to the registered office address.
If you cannot find it anywhere, contact HMRC using the Self Assessment contact details on GOV.UK.
How to get a UTR if you do not have one
You get a UTR by registering for Self Assessment. Follow our step-by-step guide to registering for Self Assessment. The registration deadline is 5 October after the end of the tax year in which you became self-employed or had untaxed income. If you have missed that date, see what to do.
How long does a UTR take?
You usually get your UTR by post around 15 days after you register. It takes longer if you live overseas. Your Government Gateway activation code for the online account is sent separately. Register early, at least a few weeks before you need to file, so you are not waiting on the post in January.
When do you need your UTR?
- To file your Self Assessment tax return.
- To pay your tax bill. See how to pay your Self Assessment tax bill.
- To prove your self-employed status when working under the Construction Industry Scheme. See CIS tax returns.
- To open some business accounts or register for platforms that ask for tax details.
Is a UTR the same as a Taxpayer Identification Number?
For UK taxpayers, your UTR is often what overseas forms ask for as a tax identification number. We explain this in our guide to the taxpayer identification number.
Keep your UTR safe
Treat it like a bank detail. Share it with your accountant, HMRC and the clients that need it, and be cautious of emails or texts asking you to send it, as these can be scams.
UTR, National Insurance number and Government Gateway: how they differ
| Identifier | What it is | Used for |
|---|---|---|
| UTR | 10-digit tax reference | Self Assessment, paying tax, proving self-employed status |
| National Insurance number | Two letters, six digits and a letter | Your National Insurance record, payroll, benefits |
| Government Gateway user ID | Login for online HMRC services | Signing in to your tax account |
| Company number | Companies House registration number | Identifying a limited company, not the same as a UTR |
People often mix these up, especially when a form asks for a “tax reference”. If it asks for 10 digits, it wants your UTR. If you are unsure, check the wording on the HMRC letter or form.
Individuals, partnerships and companies each have their own UTR
- Sole traders and individuals have a personal UTR, issued when they register for Self Assessment.
- Partnerships have a separate partnership UTR, and each partner also has their own personal UTR. The partnership return uses the first and your personal return uses the second.
- Limited companies have a Corporation Tax UTR, which is sent when the company registers with HMRC. It is not the same as your personal one.
- Landlords use their personal UTR if they report rental income through Self Assessment.
What to do if your UTR has not arrived
- Wait the usual 15 days, plus a few extra days if you live abroad or the post is slow.
- Check that you used the correct address when you registered. A mistyped postcode is a common cause.
- Look in your HMRC online account, because the UTR may already be visible there even though the letter has not arrived.
- If you still have nothing after three weeks, contact HMRC through the Self Assessment helpline or webchat shown on GOV.UK.
- Do not wait until January. If you are close to a deadline, tell HMRC straight away that you are waiting on your UTR so it is on record.
If you live outside the UK
People living abroad can still register for Self Assessment, for example to report UK rental income. The UTR is posted to your overseas address, which takes longer, so apply well before the deadline. Our non-resident landlord tax return service can help with this, and this guide explains the tax rules.
Using your UTR safely
- Never post your UTR on social media or share it in public forums.
- HMRC will never ask you to confirm your UTR by clicking a link in a text or email. Treat unexpected messages as suspicious and sign in via GOV.UK instead.
- Give it to your accountant or tax adviser securely, and keep a copy in a safe place.
- Check your HMRC letters carefully. Fraudsters sometimes copy the layout of real notices.
Common questions people have about their UTR
Does it expire? No. Your UTR stays the same for life, even if you stop being self-employed for a while and later restart. You do not need a new one each tax year.
What if I stopped self-employment years ago? The number is still yours. If you restart, contact HMRC to reactivate your Self Assessment account rather than registering again, which can create confusion.
Do I need a UTR if I am an employee? Only if you have to file a return, for example because of untaxed income, high income, or rental profits. Most employees taxed through PAYE do not need one.
Need help getting set up?
If you are starting out or catching up, we can help you register, collect your figures and file on time. See our Self Assessment tax return service or get a fixed-fee quote.
Frequently asked questions
How do I find my UTR number?
Check your online personal tax account, the HMRC app, and any old HMRC letters such as a notice to file a tax return. If you cannot find it, contact HMRC.
How long does it take to get a UTR?
HMRC usually posts your UTR around 15 days after you register for Self Assessment. It can take longer if you live outside the UK.
Is my UTR the same as my National Insurance number?
No. Your UTR is a 10-digit number used for Self Assessment, while your National Insurance number is a different identifier made up of letters and numbers.
Can I get a UTR for my limited company?
Yes. A limited company has its own Corporation Tax UTR, which it can request online and HMRC posts to the registered office address.
Do I need a UTR to be self-employed?
You need one if you must file a Self Assessment return, which includes most self-employed people with income above the £1,000 trading allowance.
Want an accountant to do it for you?
Our qualified accountants prepare and file your return for a fixed fee, agreed before we start. Get a free quote, see our prices or call 0203 4411 258.
Last reviewed 28 October 2026. This guide is general information for UK taxpayers and is not personal tax advice. Scottish income tax rates differ from those shown.
Sources
Need help with your tax return?
Qualified Accotax accountants prepare and file it for a fixed fee, from £199 + VAT.
Get my free quote See pricing
Accotax is a London firm of qualified accountants and tax consultants, on the ICAEW approved employers list. Our team prepares Self Assessment, landlord and company tax returns every day, and each guide is checked against GOV.UK before it is published and updated every tax year.
Reviewed and kept up to date by our expert team of ICAEW, ACCA and AAT qualified accountants. Last updated . This page is general guidance, not personal advice.
