2020-2021 Split year treatment

Hi. I arrived to UK under BNO visa on Feb 2022 and realised that I might have to apply for split year treatment as i have income in Hong Kong during 2021. I checked that I do not have to fill out Self assessment form as no income after arrived UK. Can I confirm if I have to apply for split year treatment? If so, can I apply now and how do I apply? Thank you.

Hi Leo,
If you qualify for split year then you only report any foreign income for the UK part of the year:
RDRM12000 - Residence: The SRT: Split year treatment: Contents
If you do not qualify then you will need to report all your foreign income to the UK:
Tax on foreign income
The guidance at RDRM12150 at www.gov.uk will help you work out if split year treatment applies. 
Thank you.