Find your lost Unique Taxpayer Reference

Your Unique Taxpayer Reference (UTR) is a 10 digit number. You’ll find it on letters from HMRC about Self Assessment.

Where to look

  • your notice to file a tax return
  • a previous Self Assessment statement
  • the welcome letter you got when you registered

If you still cannot find it

You can ask HMRC to post it to you. It usually arrives within 15 working days.

You need your UTR to sign in and file your tax return.