How to activate Self Assessment
To enable electronic submission of Self Assessment you must have a Government Gateway ID which has the Self Assessment service activated, otherwise any attempt to submit will be rejected with an Authentication Error (the same error you would see if you typed the password incorrectly).
To activate Self Assessment, which is also referred to as 'enrolling in Self Assessment' or 'adding the Self Assessment tax to your account':
- Sign in to the HMRC website (https://www.gov.uk/log-in-register-hmrc-online-services) using your Gateway ID
- Within your personal tax account, look for a 'Self Assessment' heading and click on the link to open the 'Your Self Assessment' page. If that displays a link to 'Complete your tax return', you have already activated the Self Assessment service. If, instead, it contains a link to instructions on how to enrol for Self Assessment, or add Self Assessment to your account, click that link and follow the instructions.
- HMRC will then post an activation code to the UK address you provide. When that arrives (which typically takes a few working days but could take longer), sign in to the HMRC website using your Gateway ID, then type that code in as instructed, to complete the activation process.
The form to activate Self Assessment requires you to enter a UK address and a National Insurance number (NINO). If you do not have one or both of those, the current advice from HMRC is that you should submit on paper using the official HMRC forms which can be downloaded from https://www.gov.uk/self-assessment-tax-return-forms. You will need to download any relevant supplementary forms as well as the main form (SA100 or SA800).
Note that a printout of the PDF export from our software cannot be used as a paper submission - HMRC require that their official forms are used.
For any queries regarding activating Self Assessment, please contact HMRC Online Technical support: https://www.gov.uk/government/organisations/hm-revenue-customs/contact/online-services-helpdesk