A UTR is the 10-digit reference HMRC uses for your Self Assessment. You do not apply for one on its own: it is issued when you register for Self Assessment or set up a limited company. Here is how to get it, how long it takes and where to find it if you have lost it.
Register for Self Assessment as a sole trader. Do it online, or by post with form CWF1 if you cannot register online.
You are not self-employed
Register for another reason, such as property, trust or pension income. Online, or by post with form SA1 if you cannot register online (see the SA1 form guide).
You have a limited company
You get a UTR when the company is set up. If you cannot find the Corporation Tax UTR, request it online and HMRC will send it to the address registered with Companies House.
How to get a UTR
1
Check you need to register
You must register by 5 October 2026 if you need to send a tax return for the 2025 to 2026 tax year and have not sent one before. If you registered before but did not send a return last year, you may need to reactivate your account instead.
2
Register for Self Assessment
Use GOV.UK's registration service. You sign in to register, and can create sign-in details if you do not have any. You can save your progress and come back later. You cannot register online if you do not live in the UK.
3
Collect your UTR
Online: it will be in your personal tax account within 72 hours. By post: usually 15 working days, 21 days if you are abroad, and sooner if you have a personal tax account or the HMRC app.
4
Use it to file and pay
You need your UTR to file the return online, and your 11-character payment reference is the UTR followed by K. Send the return by the deadline and pay the tax bill by 31 January 2027.
Where to find a UTR you already have
GOV.UK lists these places for individuals and sole traders:
Personal tax account
Sign in to your personal tax account to see your individual UTR.
HMRC app
Your UTR is also in the HMRC app.
Old returns and HMRC letters
Check previous tax returns and other HMRC documents, such as notices to file a return or payment reminders. A company, partnership or trust UTR is found the same way.
Contact HMRC
If you cannot find your UTR on any documents or online, contact HMRC.
Common problems
UTR not arrived? After the usual wait, use HMRC's tool to check when you can expect a reply.
Registering after 5 October 2026 (for the 2025 to 2026 return)? HMRC will send you an email or letter confirming your return deadline, and you could get a penalty.
Filing for the first time? You must register for Self Assessment before you can use the online filing service.
Registered before but no return last year? You may need to reactivate your Self Assessment account instead of registering again.
Using an agent
You must register for Self Assessment before you can authorise an agent for it, so get your UTR first. The 64-8 form guide and the SA1 form guide below cover the agent authorisation form and the postal registration form.
Frequently asked questions
What is a UTR number?
A UTR is a Unique Taxpayer Reference, a 10-digit number HMRC gives you when you register for Self Assessment or set up a limited company. It might just be called 'tax reference' on your HMRC letters.
How do I get a UTR number?
Register for Self Assessment with HMRC. If you register online, your UTR will be in your personal tax account within 72 hours. If you register by post, you will usually get it by post in 15 working days (21 days if you are abroad), but it may take longer during busy periods. A limited company gets a Corporation Tax UTR when it is set up.
Who needs to apply for a UTR?
You need to register for Self Assessment, and so get a UTR, if you have to send a tax return and have not sent one before. You do not apply for a UTR separately: it is issued as part of registering.
How long does it take to get a UTR?
Online registrations show the UTR in your personal tax account within 72 hours. By post, GOV.UK says around 15 working days, or 21 days if you are abroad, and sooner if you have a personal tax account or the HMRC app. If it has not arrived after that, you can use HMRC's tool to check when to expect a reply.
Where can I find my UTR number if I have lost it?
If you are an individual or sole trader, look in your personal tax account, in the HMRC app, or on previous tax returns and other HMRC documents such as notices to file a return or payment reminders. If you cannot find it on any document or online, contact HMRC.
How do I find my company's UTR?
For a company, partnership or trust, the UTR is on previous tax returns and other HMRC documents such as notices to file a return or payment reminders. If you have a limited company you can request your Corporation Tax UTR online, and HMRC will send it to the business address registered with Companies House.
Do I need a UTR to file a Self Assessment tax return?
Yes. You need to sign in to HMRC's online service and you will also need your UTR. If you are filing for the first time you must register for Self Assessment first.
What is my payment reference for Self Assessment?
Your Self Assessment payment reference is 11 characters: your 10-digit UTR followed by the letter K.
When must I register for Self Assessment?
By 5 October after the end of the tax year, if you have not sent a tax return before. For the 2025 to 2026 return that date is 5 October 2026. If you register after it, HMRC will send you an email or letter confirming the deadline for your tax return, and you could get a penalty.
I registered before but did not send a return last year. Do I need a new UTR?
No. You keep the UTR you were given, but you may need to reactivate your Self Assessment account. The registration service explains how to do that.
