Hi,
We cannot confirm whether split year treatment will apply in your circumstances. This is an informed decision that you need to make, having reviewed and undertaken the statutory residence tests here:
RDR3 Statutory Residence Test
In the situation that you are treated as UK tax resident for the whole tax year, you then need to follow the guidance on split year treatment. If you qualify for split year then you only report any foreign income for the UK part of the year. You can see guidance here:
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. Again, you can see guidance here:
Tax on foreign income
The following guidance will help you work out if split year treatment applies. In either case, a tax return is required.
RDRM12150 - Residence: The SRT: Split year treatment: Case 4: Starting to have a home in the UK only
Thank you.