To register (sign up) as an Organisation, you must enter your Corporation Tax Reference, and either your registered office postcode or your Companies House Registration Number (CRN):
Corporation Tax Reference - this can also be called the Company Unique Taxpayer Reference (UTR) and is a 10 digit number, for example 1234567890. You'll find it on the Notice to deliver the Company Tax Return and on most other documents sent by HM Revenue and Customs. Depending on the document or piece of correspondence, it may be printed next to the heading 'Tax Reference', 'UTR', or 'Official Use'
Registered office postcode - please enter the postcode of the address your company is registered with at Companies House. If you're not a limited company enter the postcode that you use for business correspondence
Companies House Registration Number (CRN) - this is allocated by Companies House when you register a company and can be up to a maximum of 8 numbers. Sometimes CRN's are preceded by alpha characters. You'll find this number on any documentation received from Companies House. A company would also normally display this on letter headings or compliment slips. If you can't find this number, please contact your tax office
Please note: When entering the CRN during registration (sign up) please leave out any preceding letters or leading zeros.
Example: CRN AB 00097609 should be entered as 97609
To register (sign up) as an Agent, you must enter your Corporation Tax Agent Reference Number and your postcode. Contact your local tax office if you don't have a Corporation Tax Agent Reference Number.