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Where do I find my company's UTR (the 10-digit tax reference)?

Updated 15 July 2026
The short answer

Your company's UTR is a 10-digit number that HMRC posted to your company's registered address soon after the company was set up. It is printed on letters HMRC has sent your company about Corporation Tax, where it might just be called "tax reference". Can't find any letter? You can ask HMRC for a copy online, and the request is quick to do. The copy is posted to your company's registered office, so it takes a few days to arrive.

Official source. This guide is a plain-English summary of official GOV.UK guidance, not advice. The authoritative source is Find your UTR number on gov.uk. Always rely on that over our summary.

What is a UTR?

UTR stands for Unique Taxpayer Reference. It is the number HMRC uses to tell your company's tax record apart from everyone else's. Think of it as your company's account number with the tax office.

Three things to know about it:

  • It is 10 digits long, numbers only.
  • On HMRC letters it is sometimes labelled just "tax reference" rather than "UTR". Same thing.
  • If you spot a reference that is 10 digits with a letter K stuck on the end, be careful: that is a payment reference from your own personal Self Assessment paperwork, so the number in front of the K is your personal tax reference, not your company's UTR. It will not work for Corporation Tax. Keep looking for a Corporation Tax letter addressed to the company.

You need it whenever you deal with HMRC about Corporation Tax: activating Corporation Tax online, filing your Company Tax Return, or ringing the helpline. Whoever asked for "your UTR" means this number.

Which letters is it printed on?

Any letter HMRC has sent your company about Corporation Tax should have it, usually near the top. The most common ones are:

  1. The very first letter HMRC sent after your company was formed. It arrives at your registered office soon after the company is set up, and it is often a form called CT41G, "Information for new companies". This letter exists mostly to give you your UTR.
  2. A "notice to deliver a Company Tax Return". HMRC sends this each year to tell you a return is due.
  3. Payment reminders and other Corporation Tax letters from HMRC.

So before anything else, dig through the company's post for anything from HMRC. Not Companies House, HMRC. If your registered office is an accountant's or formation agent's address, ask them, the letters went there.

Is my UTR the same as my company number or my Gateway login?

No, and this mix-up is the most common reason people type the "wrong" UTR. Your company has three completely different numbers:

  • Company number. From Companies House when the company is formed. It is on your certificate of incorporation and shown publicly on the Companies House website. Not your UTR.
  • Government Gateway user ID. The login you use for HMRC's website. It proves who is signing in. Not your UTR either. Lost it? See I've lost my Government Gateway login.
  • UTR. The 10-digit tax reference this page is about. It identifies the company's tax record itself.

Quick test: on a Companies House document or the public register, it is your company number. Typed into a sign-in box, it is your Gateway ID. Ten digits on a letter from HMRC, that is your UTR.

How do I get a copy if I can't find any letter?

Don't worry, this happens all the time and HMRC has a free online service exactly for it. Here is the whole rescue, step by step:

  1. Check your registered office address first. The copy is posted to your company's registered address as shown on Companies House, and nowhere else. If that address is out of date, fix it with Companies House first, then give the change time to reach HMRC before you ask for the copy. The two systems do not update each other instantly, and if you request too soon the letter can still go to the old address, somewhere you can't get it.
  2. Go to gov.uk and search "find your UTR number", then choose the option to request your Corporation Tax UTR online.
  3. Type in two things: your company registration number and your registered company name, exactly as they appear on the Companies House register.
  4. Submit it. That is the whole form. HMRC posts a copy of your UTR to the registered office. It comes by post on purpose, to keep the number out of the wrong hands.
  5. Watch the post and keep the letter somewhere safe this time. A photo of it on your phone works wonders.

One honest caveat: the service only works for companies that are registered with Companies House and still on the register. If your company has been dissolved or struck off, the online service will not help, and the right move is to ring HMRC's Corporation Tax helpline on 0300 200 3410 or speak to an accountant.

How long does it take to arrive?

The online request is quick to complete. The copy itself comes by post to the registered office, so allow a few days. It is not instant, and it is never shown on screen, that is deliberate, for security.

If you are mid-filing and waiting on the letter, use the time to get everything else ready: your figures, your Companies House authentication code, and your Government Gateway login. Then finish in one sitting when it lands.

What if my company has never had a UTR?

If you have never received any Corporation Tax letter, your company may not be registered for Corporation Tax with HMRC yet.

Most companies never think about this: registering at Companies House normally sets you up for Corporation Tax at the same time, and HMRC then writes to you with your UTR. If that didn't happen, you can add Corporation Tax services through your business tax account on gov.uk. You normally need to be registered, and have your UTR, before a return can be filed.

If your company was formed in the last few weeks, just wait: your UTR should already be on its way, and the copy service will turn you away as "recently incorporated".

The wrong-digit trap: when a typo looks like a scary error

If you type your UTR with one wrong digit, HMRC's computer cannot match your details to your company, and your filing gets turned away with an error that looks like a serious sign-in failure. The best known one is error 1046. It looks like you are not allowed to file. Almost always it just means one of the details, often the UTR, has a typo.

So before you panic:

  • Count the digits. A UTR is exactly 10 digits.
  • Copy it straight from an HMRC letter, don't type it from memory.
  • If your number ends in a letter K, stop: that reference comes from your personal Self Assessment paperwork, not the company's. It is not the company's UTR, so find a Corporation Tax letter addressed to the company instead.
  • Make sure it is the UTR, not your company number or Gateway ID.

If you have hit that error already, our guide HMRC error 1046 explained walks through the fix. And once your UTR is right, correcting the details and sending again is normally all it takes.

Common questions

Can I look up my UTR on the Companies House website?

No. Companies House shows your company number and filings, but your UTR comes only from HMRC, and HMRC keeps it off public view for security.

Can HMRC send the copy to my home instead of the registered office?

No. The copy goes to the company's registered address exactly as it appears on Companies House. If that address is wrong or unreachable, update it with Companies House first, allow time for the change to reach HMRC, then request the copy.

My letter shows 10 digits followed by a K. Is that my company's UTR?

No. A reference ending in a K comes from your personal Self Assessment paperwork, so those 10 digits are your own personal tax reference, not your company's UTR. It will not work for Corporation Tax, so keep looking for a letter from HMRC addressed to the company about Corporation Tax.

My company is dissolved but I still need its UTR. What do I do?

The online copy service won't work for a dissolved or struck-off company. Ring HMRC's Corporation Tax helpline on 0300 200 3410, and if the situation is tangled, an accountant is genuinely the right call here.

Filing your return once you've got it?

SimpleReturns files your Company Tax Return and accounts for £99, flat, per submission. Free to start, no card needed. The connect-your-company step has a built-in rescue wizard for exactly this kind of snag, checks your sign-in details up front, and gives you a before-you-start checklist so the UTR hunt happens once, not mid-filing.

Start your return

And if your company's situation is unusual, say it is dissolved, part of a group, or mid-dispute with HMRC, an accountant may honestly be the better fit.

General guidance, not advice. This guide explains how the rules generally work for small UK limited companies. It isn't tax advice for your specific situation, if you're unsure, check with us or an accountant.