Register for and file your self assessment tax return

File your tax return online 

You can use the online service to: 

  • fill in and send your tax return to HM Revenue and Customs (HMRC) 
  • go back to a tax return you have already started 
  • check your details, view returns and print your tax calculation 

You will need to register for Self Assessment again if you have sent a tax return in the past but you did not have to send one last year. 

If you are filing online for the first time 

You must have received your Unique Taxpayer Reference (UTR), enrolled for the online service and activated your account using the code you received in the post. 

How you do those things depends on whether you are: 

If you have not told HMRC you need to send a return 

There are different ways to register for self assessment:

You should allow enough time to complete the registration process so you can send your return by the deadline (external link). 

HMRC guidance videos

HMRC have provided some useful step-by-step guides on online registration via YouTube:

When you cannot use the service 

You need to use commercial software (external link) or download other forms (external link) to send a self assessment tax return: