declaring non-uk tax residency

For HMRC, Hello - After graduating from university, I left the UK to work abroad in Asia for a foreign owned company - I didn't plan on staying for more than a year. However the circumstances of COVID left me without means of return, and following on from this I ended living abroad long-term due to the work opportunities. To date I have been living abroad for almost five years (since September 2019). In 2023 I spent approximately 14 days in the UK. Based on current plans in 2024 I will have spent approximately 35-40 in the UK before January 1st 2025. Since September 2019 all the rest of my time has been spent abroad. I have not received any income from the UK since I left, I don't own / haven't owned any property in the UK, and have had no other UK investments, business income or work contracts. Sole income has been from foreign employers, this is already taxed under my foreign tax code - (some funds were sent back to my uk accounts 2024 - approx. 7000, 2023 - approx. 12,500, 2022 - approx. 2000) Recently I was researching the possibility of setting up an investment stocks and shares isa account to invest with. I learned that because my income and residence has changed from the UK that an isa account is not possible, and that I should have declared non-residence tax status already. I just want to know - 1. How to declare non-residence tax status? 2. Is it possible to back-date non-residence tax status? (I was unaware that I needed to do this until recently, as to date I have never done any of my own accounting - since all of this was taken care of by my employers for me). 3. Are there implications / liabilities for having failed to do this sooner - what do I need to be aware of. 4. If I can successfully declare non-residence; then what would the implications be for capital gains with a stocks and shares account, and what information would I need to share about capital gains - either with HMRC or a Broker. Thankyou for any information you can provide.

Hi,
You can only open an ISA, if you are a UK tax resident in that tax year and you can only pay into ISA's up to the end of the tax year in which you left the UK.  
You cannot backdate this in any way.
As you left the UK in Sept 2019, your foreign income from then til now is not taxable in the UK and you do not declare it in the UK.
You can complete form P85 (Get your Income Tax right if you're leaving the UK (P85)) to confirm that you are no longer resident in the UK.  
You will need to seek advice from your broker, regarding your account with them.  
You will also need to check whether there is a tax treaty with your country of residence and check the article relating to capital gains. (Tax treaties) as you
may have to pay capital gains tax in the UK.
Thank you.

thankyou for the information

Sorry to bother you again, but I have a couple of follow-up questions also; 1. How does non-UK tax resident status affect my ability to make National Insurance contributions? Can I still do this? 2. About the Capital Gains Tax again- the country in question is China; where I have a tax code, now as far as I can understand it - once the P85 is filed, any capital gain on any income sourced form China that is invested - would be taxed under the Chinese tax code only for that year. Is this correct?

Hi jozmarv

1. please refer to National Insurance: introduction  
2. capital gains will be due in the country you are resident so if sold after you left the UK then yes this will be China

Thank you