Portugal/UK Double Tax Agreement UK Pension

I am a UK National but became a Portuguese tax resident some years ago. I started to receive a UK pension income from my UK SIPP in tax year 22/23, UK tax has been deducted at source via PAYE. I understand this pension is only taxable in Portugal, as per Article 17 of the DTA, is this correct? I file UK Tax Returns to declare UK rental income. Can you please confirm that I do not need to include income from this pension on my UK Tax Return. Do I still need to complete form HS304 and attach this to my 23/24 Tax Return? I am out of time to amend my 22/23 Tax Return electronically, do I have to file a revised 22/23 Tax Return and HS304 by paper? Finally, can you please confirm that I can complete a form DT-Individual and submit this to HMRC to obtain an NT code going forward, to avoid the need to reclaim tax in future years? Thanks.

Hi
For 2024 to 2025 onwards you should submit a completed DT individual form (Double Taxation: Treaty Relief (Form DT-Individual)) and send it to the Portuguese tax authorities.  They will return it to you, so that you can attach a Portuguese certificate of residence with a ‘No Contribuinte’ (TIN) and ‘Cod Vaidacao’ (Validation Code).  This will allow us to arrange for any tax in the current year to be repaid and prevent further tax being deducted.  You can still amend your 2022 to 2023 tax return up to 31 January 2025, including online amendments.  You should be able to attach the completed HS304 and certificate of residence to your online return.  Any paper amendments of any kind,must be in HMRC possession by that date.  A HS304 (Non-residents tax relief under double taxation agreements (Self Assessment helpsheet HS304)) will be required for each year that you are declaring the pension as not taxable in the UK.