How to apply for a UTR number: Online, phone, and post

Team Nomi

Sep 01, 2026
7 minutes read

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UTR, or Unique Taxpayer Reference, is a 10-digit number issued by HM Revenue and Customs (HMRC) to identify you for tax purposes in the UK. If you’re self-employed, run a business, or need to file a self-assessment tax return, you’ll need a UTR number.

In this blog, we will explain how to apply for a UTR number and discuss the various methods for applying online, by phone, and by post. You will learn who needs a UTR, when to apply, and how to find a lost number. Also, address common issues and provide tips to ensure a smooth application process.

Remember, your UTR is essential for managing your tax affairs, so it’s important to apply it correctly and keep it safe. Whether you’re a freelancer, contractor, or business owner, this will help you navigate the UTR application process with ease.

What is a UTR number?

Your UTR is essentially your personal tax ID with HMRC a 10-digit code, always starting with a digit between 1 and 9, that stays with you (or your business) for life. It’s different from your National Insurance number and different from your company registration number, so don’t mix them up.

You’ll find it printed on official HMRC correspondence: tax returns, payment reminders, and your Self Assessment statements.

Who needs a UTR number?

You need a UTR if you fall into any of these groups:

• • Self-employed people and freelancers
  • Sole traders and business partners
  • Company directors
  • Landlords with rental income
  • High earners (over £100,000 a year)
  • Anyone with significant savings or investment income
  • People claiming certain tax reliefs or deductions
  • Those with foreign income or working abroad
  • Ministers of religion

Even if you’re on PAYE, additional income or a more complex tax situation can still mean you need to register.

How to Apply for a UTR Number Online

Online is the fastest route, and it’s completely free.

1. Go to HMRC’s registration page at gov.uk/register-for-self-assessment
2. Pick the option that fits you – sole trader, partnership, or limited company each have a slightly different path.
3. Set up a Government Gateway account if you don’t already have one; you’ll need it to complete the application.
4. Fill in your details – full name, date of birth, National Insurance number, address, and phone number. Double-check everything, since mistakes here are the most common cause of delays.
5. Answer a few questions about your work – what you do, when you started, and roughly what you expect to earn.
6. Submit and save your confirmation. You’ll get an on-screen reference the moment you finish; keep it somewhere safe.
7. Wait for your UTR to arrive by post. HMRC typically sends it within 10 working days, though it can stretch to 21 during busy periods (January is the worst).
8. Set up your online self-assessment account once the UTR lands, so you’re ready to file.

A few things that make this smoother: Have your details ready before you start, use a connection you trust won’t drop mid-form, and don’t guess on anything; HMRC’s own guidance is there if you’re unsure of a question.

How to Apply for a UTR Number by Phone

If you’d rather talk it through than fill in a form, HMRC’s Self Assessment helpline can register you directly.

1. Get your information together first – name, date of birth, National Insurance number, and address.
2. Call 0300 200 3310 (Monday to Friday, 8 am-6 pm).
3. Work through the automated menu to reach the registration option.
4. Explain to the advisor that you want to register for a UTR; they’ll take it from there.
5. Answer some identity verification questions.
6. Confirm the details with the advisor before they submit it.
7. Your UTR arrives by post, again usually within 10 working days.

Calling early in the morning or later in the afternoon tends to mean shorter hold times. It’s a solid option if your situation is a bit unusual, but expect it to take slightly longer overall than applying online.

Apply for a UTR Number by Post

The slowest option, but it still works if online or phone isn’t practical for you.

1. Get the right form – SA1 for individuals, SA400 for partnerships.
2. Fill it in accurately, covering both personal and business details.
3. Check it over before sending – errors on paper forms take longer to correct than online ones.
4. Attach ID or proof of address if the form asks for it.
5. Send it by recorded delivery, so you have proof it arrived.
6. Expect 10-21 days for HMRC to process it and post your UTR back.

Write clearly, keep a photocopy of what you sent, and follow up if you haven’t heard anything after three weeks. 

What information is needed to apply for a UTR number?

Whichever method you choose, you’ll need broadly the same details on hand:

• • Personal details: full name, date of birth, National Insurance number, current address, phone number, and email.
  • Business information: business name (if you have one), business address, what your business does, and your self-employment start date.
  • Identification: a passport or driving licence.
  • Additional details: why you’re registering and a rough estimate of your income. 

When Should You Register for a UTR Number?

The general rule: register as soon as you know you’ll need a UTR, not when the deadline is looming. Here’s what typically triggers registration:

• • Starting self-employment – register as soon as you begin trading, ideally within the first few weeks.
  • Setting up a limited company – register when you incorporate, not before.
  • Joining a partnership – register once you’re confirmed as a partner.
  • Filing a tax return for the first time – leave at least 20 working days before the deadline, since post alone can take up to 21 days.
  • Earning rental income – register in the same tax year the rent starts coming in.
  • Receiving foreign income – register as soon as it begins, even if it’s irregular.
  • Selling an asset for a capital gain – register before the relevant tax year closes.
  • Would rather not do this online – call HMRC and they’ll register you over the phone instead.

How to Find a Lost UTR Number

1. Check old tax paperwork – Self Assessment returns, HMRC letters, and payment reminders all show it.
2. Log into your HMRC online account – it’s listed under your personal details.
3. Open the HMRC app – your UTR is visible once you’re logged in.
4. Contact HMRC directly – by phone, web chat, or secure message. Be ready to verify your identity.
5. Check your company records, if you’re a director.
6. Check your accounting software – most platforms store it automatically once it’s been entered.

Conclusion

Getting a UTR is a one-time task, but it’s an essential one if you’re self-employed, running a business, or dealing with rental or foreign income. Apply as early as you reasonably can – the postal turnaround catches a lot of people out right before a filing deadline.

If you’re an accountant managing this process for multiple clients, our self-assessment software is built to take the manual chasing out of it. You can try it free for 30 days here.

Frequently Asked Questions

1. How long does it take to get a UTR?
Ans. Usually 10 working days by post from HMRC, though it can take up to 21 days during busy periods like January.

2. Can I get a UTR over the phone?
Ans. Yes, call HMRC’s Self Assessment helpline, and an advisor can register you directly. Your UTR still arrives by post afterwards.

3. Can I work without a UTR?
Ans. You can start trading without one, but you’ll need to register and receive your UTR before you can file a tax return.

4. Does it cost anything to register?
Ans. No, registering as self-employed and getting a UTR from HMRC is completely free.