What Is a UTR Number? How to Find Yours for CT600 Filing
Your Unique Taxpayer Reference (UTR) is the 10-digit number HMRC uses to identify your company for tax purposes. You'll need it every time you file a CT600 or contact HMRC about Corporation Tax.
UTR vs Company Number — Don't Confuse Them
| UTR | Company Number | |
|---|---|---|
| Digits | 10 | 8 |
| Issued by | HMRC | Companies House |
| Used for | Tax returns, HMRC correspondence | Company registration, accounts |
| Example | 1234567890 | 12345678 |
| Format | Numbers only | Numbers (may start with letters like SC, NI, OC) |
These are completely different numbers issued by different government bodies. Your company number identifies your company at Companies House. Your UTR identifies it with HMRC for tax.
Where to Find Your UTR
1. HMRC Letters
Your UTR is on any letter HMRC has sent about your Corporation Tax. Look for:
- Notice to file a Company Tax Return (CT603)
- Corporation Tax payment reminders
- Any correspondence from HMRC about your company tax
It's usually in the top right corner or in the reference section.
2. Government Gateway
- Log into your HMRC Business Tax Account
- Select Corporation Tax
- Your UTR is displayed on the main screen
3. Previous CT600 Returns
If you've filed before, your UTR is on Box 3 of your previous CT600.
4. Your Accountant
If you have an accountant, they'll have your UTR on file.
Don't Have a UTR?
New Companies
When you register your company with Companies House, HMRC should automatically send you a UTR within 2-4 weeks. It arrives by post to your registered office address.
If it doesn't arrive:
- Call HMRC: 0300 200 3410 (Corporation Tax helpline)
- Or register online via Government Gateway
Lost Your UTR?
Call HMRC on 0300 200 3410. You'll need to verify your identity (company name, registration number, registered address, director details).
Filing Your CT600 with Taxpipe
When you sign up for Taxpipe, we'll ask for your UTR in the company setup step. We validate it using a checksum algorithm to catch typos before you submit to HMRC.
Know your UTR? File your CT600 now with Taxpipe — £59, 15 minutes, HMRC-validated.