What is a SA1?

SA1 is a form that is used to register for self assessment for any reason other than self employment.

Her Majesty Revenue and Customs (HMRC) needs you to complete an SA1 if you meet self assessment criteria and are not self employed.

There are several reasons for needing to complete a self assessment tax return with some of the popular ones being:

If you are looking to register for self employment you should complete form CWF1 which is specifically for the self employed or a SA400 for a partnership.

How do I submit SA1?

You can submit your SA1 online, by post and sometimes over the phone by calling HMRC.

You will need some or all of the following tax information to help complete your SA1:

  • Your reason for needing to submit a self assessment tax return.
  • Your full name.
  • Your address.
  • Your D.O.B.
  • National insurance number.
  • Phone number.
  • Email address.

To submit your SA1 online you will need to have access to your personal tax account. If you don’t already have a personal tax account you can apply to get one with HMRC.

How long does it take to process an SA1?

The SA1 registration process takes HMRC around 10 working days to complete however timescales can change depending on HMRC delays.

HMRC SA1 and your UTR

When HMRC has processed your SA1 self assessment registration form they will send you a 10 digit number through the post called a unique tax reference number (UTR number).

You will need the UTR number to submit your self assessment tax return to HMRC so its important to keep a record of it just like your national insurance number.

If you use the wrong UTR number on your tax return you may be penalised by HMRC.


Back to Top
Back to Top