The Unique Taxpayer Reference (UTR) will have been issued by HM Revenue & Customs (HMRC) when you or your client registered for Self Assessment. It is made up of 10 numbers, for example 1234567890, and can be found on the Tax Return (SA100), a 'Notice to complete a Tax Return' (SA316) or a Statement of Account. It may also be found on other documents we have issued.
Depending on the type of document issued the reference may be printed next to the headings 'Tax Reference', 'UTR' or 'Official Use'.
Please note: If you or your client have not yet registered with HMRC for Self Assessment this must be done to get the reference before you can enrol for the online service. For further information please see Registering for Self Assessment.