Unique Taxpayer Reference Number
A unique taxpayer reference or UTR is issued by HM Revenue & Customs when you register for self assessment. A UTR number is made up of ten numbers and can be found on tax return, notice to complete tax return or statement of account documents.
You will typically find that the unique taxpayer reference number is printed at the top left of any of the documents mentioned above. You should keep these documents for later reference. When calling HMRC you are often asked for this number.
