Split year treatment application

Hello I want to apply for split year treatment for the tax year 2023/24. But during the self assessment registration for my first self assessment request, I did not request the split year treatment application. May I know if I can still apply for the split year treatment while I am filing my online self assessment tax return? And how can I apply? Thank you.

Hi ,
 

Split year treatment is not part of the self assessment registration process.  If you have submitted your tax return already, you will have to submit an amendment.  To claim split year treatment, requires the completion of supplementary page SA109.  If you have still to submit your tax return, you can download a paper version at : Self Assessment tax returns  , as well as the relevant supplementary pages  .  Provided you have a government gateway user ID and password, you can use this to submit an online commercial tax return.  You can by these from the list of suppliers at : Self Assessment commercial software suppliers .  All parts of your tax return, should be submitted in the same format . Thank you .