SA109 - Submission method

Hi HMRC Admin, Wish you are doing well. I would like to submit ONLINE self assessment due to I have foreign interest from overseas bank but I only became UK resident since 1st Aug 2022. I know that I will need to submit SA109 for split year treatment. But I am confused of what method I can submit SA109 correctly. For this case, if I submit ONLINE self assessment (I think it is called SA100), can I send SA109 by post separately? Or any other methods I can consider? Thanks and looking forward to your assistance. Best regards, Ray

Hi RayL,
The form SA109 is not supported by HMRC software.
You can purchase 3rd party software which will then allow you to submit it online.
Please see:
Self Assessment commercial software suppliers
Your other option is to send the full return (SA100) and SA109 by paper.  
The dealine for this is 31 October.
Thank you.