A UTR is your Unique Taxpayer Reference. It is a ten-digit number, sometimes written with a letter K on the end, and HMRC uses it to match every tax return and payment to the right person. If you file Self Assessment, you have one or you need one.
How you get a UTR
You do not apply for a UTR by itself. It is issued automatically when you register for Self Assessment. Register as self-employed, and a week or two later a letter arrives with the number on it. That is the whole process.
The same applies to companies. A limited company gets its own UTR when it is formed, which is a different number from the director's personal one. If you run a company, keep the two apart.
Where to find a UTR you have lost
Check these before you call HMRC:
- The HMRC app, or your personal tax account on GOV.UK, under Self Assessment.
- The original "Welcome to Self Assessment" letter.
- Any previous tax return, or the calculation HMRC sent back.
- Statements, payment reminders, or penalty notices from HMRC.
- A letter from your accountant, if you have one, as they will have it on file.
If none of that works, call the Self Assessment helpline. They will confirm the number after some identity checks, and can post it to your registered address, but they will not read a UTR out to a phone number or email they cannot verify.
What you need it for
- Filing your Self Assessment return, online or on paper.
- Paying your tax. The UTR goes in the payment reference so HMRC knows the money is yours.
- Registering for the Construction Industry Scheme if you work in construction.
- Signing up for VAT or setting up a payment plan.
- Some clients and agencies ask for it before they pay you, to check you are set up correctly.
What a UTR is not
Your National Insurance number and your UTR are separate things, and having an NI number does not get you a UTR. Nor is it a VAT number. On its own a UTR proves nothing, so treat it as a reference rather than an ID, but still keep it private. Someone who has your UTR plus a few other details has a head start on impersonating you to HMRC.
Once you have it
Save it somewhere you will find it in January: a password manager, a note in your phone, the front of a folder. You will need it every year, and requesting a reminder each time wastes days you may not have close to a deadline.