Late Submission of Split Year 21-22 and Necessary to report Interest, Dividend and Capital Gain

Dear Officer, I ended my job in HK and landed to UK in summer 2021 and being tax resident on 27/09/2021. I had no employment in tax year 21-22, but I had 100GBP interest, around 400GBP Dividend including UK and USA listed security and around 5000GBP capital gain from UK and USA listed security. My questions are: 1) Do I need to submit my tax return of 21-22 for split year treatment of 21-22? 2)If yes, do I need to submit foreign(SA106) for dividend earned and capital gain(SA108) for 21-22? 3)And, what is the penalty for my late submission? Many thanks.

Hi adrian papa,
To claim split year treatment, requires the completion of a Self Assessment tax return, so yes, you will need to register for Self Assessment and submit a tax return 
Check how to register for Self Assessment
Will advise you how to register
Thank you.