Dual residency self assessment

I am a dual tax resident of the UK and another country with a dual taxation agreement. I am employed by a UK company and pay UK income tax automatically. However, the tie-break questions determine that I should pay tax in the other country instead. After completing the self-assessment and claiming UK tax relief, will my UK tax code change so that I no longer automatically pay income tax in future? Will my company be aware that my tax situation has changed or at least changed for the previous year?

Hi Cherry,
You would need to include the HS302 with your tax return so that this can be verified and then telephone to have your tax code amended going forward.
Here is a link to the guidance for HS302
Dual residency (Self Assessment helpsheet HS302)
Thank you. 

Thank you for your reply. So if I don't telephone then my tax code will stay the same? Since I might want to keep it as is for the following year. And in that case my company would be unaware of any tax changes?

Hi Cherry,
That is correct.
Thank you.

I would like to ask a question about which country would have taxing rights between the US and the UK. Including the current year I have been a US tax resident for 11 out of the last 20 years although in recent years I have been resident in the UK (and non-domiciled). As the result of the recent Budget and the withdrawal of the non-domicile status I want to see if dual residency status may be beneficial in my case. In 2025 I intend to obtain a Green Card and expect to pass the US Substantial Presence Test in that year. It also seems likely that I will be UK tax resident in 2025/26 making me a dual tax resident. My US income is made up of pension income including a Social Security pension, interest, dividends, royalties and some business income whereas my UK income is made up of interest, dividends and a small amount of business income. I'm assuming that as far as my UK tax return is concerned (for 2025/26) I could claim relief (using HS302) from most of the US income (interest, dividends, royalties and work pensions).Is that correct? What would be the position regarding the US Social Security Pension and the US Business income? I also have income from some offshore funds which produce interest, dividend income and gains. Please confirm that the tie-breaker rules would decide which country would have taxing rights over this source.

Hi,
You will need to read the tax treaty between both countries and may your informed decision.  
We cannot advise if dual citizenship is beneficial or not, of the outcome of tiebraker rules.  
You may need to consider seeking financial advice for answers to these questions.
Thank you.

Thank you for your prompt response. Having read the US/UK tax treaty the tie breaker rules indicate that the UK would have taxing rights for 2025/26. As I mentioned in my original post I receive a US Social Security pension as well as a number of other pensions relating to past employments in the US. As far as the US Social Security pension is concerned it seems to me that under para 3 of Article 17 that would be taxable in the UK. What I am not entirely clear about is the situation in respect of the pensions from past US employments (dealt with under para 1(b) of Article 17). Would the income from these pensions (payable in the US) be taxable in the UK in 2025/26 if I were dual resident?

Hi ,
 

Please refer to additionakl guidance at : DT19852 - Double Taxation Relief Manual: Guidance by country: United States of America: Treaty summary  .

Thank you .