Self Assessment: register a partner for Self Assessment if they're not an individual (SA402)

Use the online service or the postal form to register a partner who is not an individual for Self Assessment, for example a company or trust.


Online form service (sign in using Government Gateway)

Print and post form (SA402)

Print and fill in by hand (PDF version)

This file may not be suitable for users of assistive technology.

Request an accessible format.
If you use assistive technology (such as a screen reader) and need a version of this document in a more accessible format, please email Please tell us what format you need. It will help us if you say what assistive technology you use.


Use the SA402 to register a partner who is not an individual for Self Assessment. The person responsible for the partner, for example the trustee or company secretary, should sign the form.

To register you can:

  • use the online service
  • fill in form on-screen, print and post to HMRC

To use the online service, you need a Government Gateway user ID and password.

If you do not have a user ID you can create one when you use the service.

Fill in the form fully before you print it as you cannot save a partly completed form so you should gather all your information together before you start to fill it in.

If you have problems opening the online forms you can use the PDF version, you’ll have to print this and fill it in by hand before posting it to HMRC.

Before you start

If you’re using an older browser, for example Internet Explorer 8, you’ll need to update it or use a different browser. Find out more about browsers.

HMRC is creating new versions of their forms that do not depend on Adobe Reader. While this work is in progress, the following methods can be used to make sure the form will download or open in Adobe Reader:

  • Windows users should right click on the form link then select ‘Save target as’ or ‘Save link as’
  • Mac users should right click on the form link then select ‘Save linked file as’
  • save the form - the recommended place is in the documents folder
  • using Adobe Reader you can open the form

If you are using a browser other than Internet Explorer you can review your settings to make Adobe Reader the default program for opening PDF documents. If the form still does not open, for further advice contact the Online Services helpdesks.

64-8: Authorising your agent

Published 15 July 2014
Last updated 20 December 2018 + show all updates
  1. The Welsh version of this page has been updated.

  2. Rates, allowances and duties have been updated for the tax year 2016 to 2017.

  3. An online service is now available.

  4. Welsh version of SA402 added to the page.

  5. First published.