UTR
The Unique Taxpayer Reference (UTR) will have been issued by HM Revenue &
Customs when you or your client registered for Corporation Tax. It is made up
of ten numbers, for example 1234567890, and can be found on the Notice to
deliver the company tax return (CT603). 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’.