Self assessment split year - move out from UK

Dear Sir or Madam, I'd like to clarify something before submitting my self-assesment tax return. I'm a British citizen and have lived, been a uk resident and had my only home in the UK for 6 years. On 15th of January 2023 I left the UK and moved to Portugal (which has DTA with the UK), where I became a resident in 2023 and have my new home. I had 2 sources of income throughout all 2022/23 tax year, a PAYE employment in the UK that ended on 30/06/2022 and started as self employed with a UK company on 04/07/2023 which I kept even after my move to Portugal, from where I work remotely. I've done all the tests required for the self-assesment and have concluded that:  1.⁠ ⁠I'm deemed a UK resident for the 2022/23 tax year.  2.⁠ ⁠I'm eligible for split year treatment due to Case 1 (starting full-time work overseas) and Case 3 (ceasing to have a home in the UK)  3.⁠ ⁠For the split year treatment, the UK part of the tax year goes until 16/01/23 , and the overseas part of the tax year is from 17/01/23 until 05/04/23.  4.⁠ ⁠During the overseas part of the year, I received 3 salary payments, while working from Portugal. My question is: According to the "Residence, remittance basis etc notes" for Box 3: "the tax year will be split into a UK part and an overseas part and you’ll pay tax only on the income arising in the UK part of the year." Since I moved countries and this is my first year working as self employed, I'd like some advice on: - in my case, because I wasn't taxed yet on that income should I just declare the total income received in that tax year as the total amount minus the 3 months where I was already a resident in Portugal? - if I need to declare the total amount, which box of the SA109 FORM should the income received during the overseas part of the tax year be added to. Box 20, 21 or 22? Also, the amount to be included there is the amount of the income or the tax to be paid for that period? I know that for the second case I also need to fill in the appropriate claim form in ‘Helpsheet 302’ or ‘Helpsheet 304’ and send this as well, but for the first case do I need to do the same? Thanks in advance for your support, Best regards,

Hi 

For the UK income, declare only the amount up to the date you left but declare all the tax deducted and this will work out the refund for you.
You cannot file online as the residence section is not supported with HMRC software and will need to purchase 3rd party - Self Assessment commercial software suppliers.
You should still include the HS304 to clarify.

Thank you