Late apply for Split Year Treatment

I would like to ask some questions as to the apply for split year treatment. My friend moved to UK in mid 2023 and became a UK tax resident in the tax year of 2022/23. She has UK property income in that year and therefore reported it in self assessment form. However, until lately she aware that she has foreign incomes in the period before she come to UK for which she DID NOT reported. She has checked that she is qualify for CASE 4 of Split year treatment and the said foreign incomes are arosed in the "Overseas Part". Qurestion on Timing: Can she apply for split year treatment for 2022/23 now and when is the deadline? Question of forms to file: Is there a special form to fill in for amendment to 22/23 form filed? Or shall she just fill in a new set of self-assment forms for 22/23 and file to HMRC again?

Hi,
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.
If you do not qualify then you will need to report all your foreign income to the UK Tax on foreign income.
As the income is for the overseas part of the year, it is ok not to be declared but she should still send in the SA109 to confirm, this cannot be filed online with HMRC software.
Thank you.

Thank you for your reply. How to amend her 22/23 self-assessment form to apply split year treatment for 22/23? When is the deadline for such amendment?

Not HMRC...if your friend came to the UK in "mid 2023" as you state, and this is after 5 April 2023 then this is 23/24 not 22/23 and split year considerations would be for 23/24 not 22/23. That said, if you meant mid 22, or before 6 April 2023 its 22/23...other than that what HMRC said applies.

Hi,
Please refer to guidance at:
Self Assessment tax returns: If you need to change your return
Thank you

Thanks Clive , just typo. It was mid 22

Thanks for HMRC's reply. The original 22/23 self-assessment form is filed via HMRC website Now the 22/23 amended form has to include SA109 and not being supported by HMRC. Can I use 3rd party software to file an amendment of self assessment return? If not by what way I can do it?

Hi,
If you submitted your tax return online and now want to amend that return, you would need use a commercial return to submit the residence section to claim split year treatment.  You can only do this up to 31 January 2025, after which it will be to late to amend your tax return.  After thid date, you would have to submit an overpayment relief claim
(see:Self Assessment Claims Manual).
Thank you.