A Corporation Tax UTR is the 10-digit Unique Taxpayer Reference that HMRC assigns to a UK limited company to identify it for all Corporation Tax purposes, from filing the CT600 to paying the bill. The number stays with the company for its whole life, regardless of changes to name, directors, or activities. HMRC posts it to your registered office shortly after the company is incorporated.
What the Number Looks Like
It is always 10 digits. Some HMRC letters show a 13-digit reference instead; the first three digits identify the tax office, and the UTR is the final 10. When a form or piece of filing software asks for your UTR, use only those last 10 digits.1HMRC patterns for services. Unique Taxpayer Reference
The Corporation Tax UTR is not the same as any other number your company holds. It is separate from the VAT registration number, the PAYE employer reference, and the Company Registration Number issued by Companies House. Individuals who file Self Assessment also have a personal UTR, but that belongs to the person. A director who runs a limited company will therefore have two different UTRs.2GOV.UK. Find Your UTR Number
How You Get One
When you register a company through Companies House, you are normally set up for Corporation Tax at the same time, unless the company is dormant.3GOV.UK. Set Up a Private Limited Company – Register Your Company HMRC then sends form CT41G to the company’s registered office. That letter contains the UTR and sets out the company’s Corporation Tax obligations. Delivery usually takes a couple of weeks; HMRC does not publish a guaranteed timeframe for UK-incorporated companies.
Once you have the UTR, you still need to activate online services before you can file returns or view your Corporation Tax statement. Sign in to your business tax account with your Government Gateway credentials, choose “Services you can add,” and enrol for Corporation Tax. HMRC then posts an activation code to the registered office within 10 days, or 21 days for overseas addresses.4GOV.UK. Add Corporation Tax Services to Your Business Tax Account
If HMRC Didn’t Set You Up Automatically
If your company was not registered for Corporation Tax at incorporation, you must tell HMRC within three months of starting any business activity. That phrase is broader than most people expect: it covers trading, receiving income of any kind (including bank interest on a company account), and claiming tax reliefs. Missing the three-month window can trigger a failure-to-notify penalty, though coming forward before HMRC contacts you results in a lower minimum penalty, and a reasonable excuse notified promptly can remove the penalty altogether.5GOV.UK. Compliance Checks – Penalties for Failure to Notify – CC/FS11
To register, you will need:
- Your Company Registration Number, the 8-character identifier on the certificate of incorporation. Older numbers can be shorter and are padded with leading zeros.6Companies House. What Is the Company Number
- The date business activity started, meaning the day the company first traded, received income, or provided services. This sets the start of your first accounting period.
- A Standard Industrial Classification (SIC) code describing what the company does. At least one is required.7Companies House. Nature of Business – Standard Industrial Classification (SIC) Codes
How to Find a UTR You’ve Lost
The quickest place to look is any letter HMRC has already sent the company. The UTR appears on the notice to deliver a Company Tax Return, on payment reminders, and on other Corporation Tax correspondence. On HMRC documents it is labelled “tax reference” and sits near the top of the page. If you see a 13-digit number, take the last 10 digits.8HM Revenue & Customs. Completing Your Company Tax Return – Section: Tax Reference
Filing software will also store the UTR if the company has previously submitted a return. If none of these turn it up, request the UTR through HMRC’s dedicated online service. HMRC will post it to the address registered with Companies House, so make sure that record is current before you ask.2GOV.UK. Find Your UTR Number
Using the UTR to Pay Corporation Tax
You cannot pay Corporation Tax by quoting the 10-digit UTR alone. HMRC uses a 17-character payment reference that changes each accounting period, and using the wrong one can delay your payment being allocated.9GOV.UK. Pay Your Corporation Tax Bill – Make an Online or Telephone Bank Transfer The structure is:
- Characters 1 to 10: the 10-digit UTR.
- Characters 11 to 14: the fixed segment A001, marking the payment as Corporation Tax.
- Characters 15 to 16: the accounting period number, starting at 01 for your first period and rising by one each year.
- Character 17: a fixed final letter A.
So a company with UTR 1234567890 paying for its second accounting period would use 1234567890A00102A. The correct reference for each period appears on the notice to deliver a return and in the Corporation Tax statement inside your HMRC online account. If you have saved HMRC as a payee at your bank, the reference stored there is for a previous period, so update it before every payment.9GOV.UK. Pay Your Corporation Tax Bill – Make an Online or Telephone Bank Transfer
Non-Resident Companies
A company incorporated outside the UK can still need a Corporation Tax UTR, but it does not get one through Companies House. Registration is required if the company trades through a UK permanent establishment, disposes of UK property or land, or is otherwise UK-resident for tax. These companies register directly with HMRC. HMRC aims to process the registration within 15 working days, but delivery of the UTR letter to an overseas address can take 2 to 8 weeks, and the separate activation code takes a similar amount of time.10GOV.UK. Corporation Tax for Non-UK Incorporated Companies
Dormant Companies
A company that has never traded does not need to register for Corporation Tax and will not receive a UTR until it becomes active. If a previously active company goes dormant, tell HMRC using the company name, UTR, and the date trading stopped; once HMRC accepts the dormant status, no further Company Tax Return is required unless HMRC asks for one or the company starts trading again.11GOV.UK. Tell HMRC Your Company Is Dormant for Corporation Tax Watch the definition: any income at all, including small amounts of bank interest, means the company is not dormant for HMRC purposes. If a dormant company starts trading or receiving income, you must register (or re-register) within three months.