How Do I Find My Corporation Tax Number?
It sounds like it should be simple. But if you have just incorporated a limited company, or you need to file a tax return and cannot lay your hands on the right reference, your Corporation Tax number can feel surprisingly elusive. You might have three browser tabs open and still not be sure what you are looking for.
This guide clears that up. It explains exactly what your Corporation Tax number is, where to find it, what to do if it has gone missing, and why getting hold of it matters for your ongoing tax obligations.
What Is a Corporation Tax Number?
Your Corporation Tax number is formally known as a Unique Taxpayer Reference, or UTR. It is a 10-digit code that His Majesty’s Revenue and Customs (HMRC) uses to identify your company for all Corporation Tax purposes. You will sometimes see it labelled as a Corporation Tax reference, a company UTR, or simply a tax reference. These all refer to the same number.
It is worth knowing what your UTR is not, because several other reference numbers are in circulation and they are easy to confuse:
- Company Registration Number (CRN): An 8-character code issued by Companies House when your company is incorporated. It identifies your company on the public register but has nothing to do with your tax affairs.
- VAT Registration Number: A 9-digit number issued by HMRC if your company registers for VAT, either compulsorily once turnover exceeds £90,000 or voluntarily before that point.
- PAYE Reference Number: Issued by HMRC when you register as an employer. Used for payroll submissions and National Insurance contributions.
- Director’s Personal UTR: As a company director who files a Self Assessment tax return, you will also hold a separate personal UTR for your own income tax. This is not the same as your company’s UTR, and the two should never be mixed up when filing or making payments.
The company UTR is the one you need for Corporation Tax: filing your CT600 Company Tax Return, paying Corporation Tax, and writing to HMRC about your company’s tax account.
How Does a Company Receive Its Corporation Tax Number?
You do not apply for a UTR directly. HMRC issues one automatically when your company is registered at Companies House. The two organisations communicate behind the scenes, and once incorporation is confirmed, HMRC creates a Corporation Tax record for your business and posts a letter containing your UTR to your registered office address.
This letter, which may be headed Notice to deliver a Company Tax Return or a similar welcome notice, normally arrives within 15 working days of your Companies House registration date. Your 10-digit UTR will be displayed clearly near the top of the document, sometimes alongside a form known as a CT41G, which outlines your initial Corporation Tax obligations.
If your registered office address changed after incorporation and was not updated promptly at Companies House, HMRC may have sent the original UTR letter to an old address. It is worth checking this first if the letter never arrived. You can verify and update your registered address at any time using the Companies House online service.
Where to Find Your Corporation Tax Number
If your company has been active for a while, the UTR will appear in more places than you might expect. Here are the most reliable sources.
HMRC Correspondence
Your UTR appears on virtually all official letters and notices that HMRC sends to your company. The label will say “Corporation Tax Reference,” “UTR,” or “Unique Taxpayer Reference.” Worth checking:
- The original UTR welcome letter sent after incorporation
- Notices to file a Company Tax Return
- Corporation Tax payment reminders
- Statements of account
- Any acknowledgement of a previously submitted CT600
If you have a filing cabinet or an email folder for HMRC correspondence, start there. The UTR is usually in the top right-hand corner of the letter.
Your HMRC Business Tax Account
If your company is enrolled for Corporation Tax online, sign in to your HMRC Business Tax Account using your Government Gateway credentials. Navigate to the Corporation Tax section and your UTR will be displayed on the dashboard. This is often the quickest option if your paperwork is not well organised.
Previous CT600 Company Tax Returns
If your company has already filed at least one Company Tax Return, the UTR appears on the front page of the CT600 form. Check your accounting software, any digital copies of previous returns, or the files held by your accountant.
Your Accountant or Tax Adviser
This is often the most direct route. If you use an accountant for your Corporation Tax, they will have the UTR on file. It is included on every CT600 they submit and every piece of HMRC correspondence they handle on your behalf. A quick email or call will usually get you the answer within minutes.
What to Do If You Have Lost Your Corporation Tax Number
If none of the above has turned anything up, do not worry. HMRC can reissue your UTR, though for security reasons they will not confirm it over the phone. Instead, they send a letter to your company’s registered office address, which typically takes 10 to 15 working days.
There are two ways to get a replacement:
- Online: Use the HMRC Find your UTR number service on GOV.UK. HMRC will send the UTR to the business address registered with Companies House, so make sure that is current before you submit the request.
- By telephone: Call the Corporation Tax helpline on 0300 200 3410. You will need your company name, Company Registration Number, registered office address, and director details to pass the security checks. HMRC will then issue a letter rather than giving the number verbally.
Try to sort this out well before any filing or payment deadlines. Without your UTR, you cannot submit a Company Tax Return or make a Corporation Tax payment through the correct channel, which can result in late filing penalties even if the accounts themselves are ready to go.
