US expat, UK tax resident.

[JayCee2]

I am a dual UK and USA citizen, tax resident in the UK. I have capital gains from sales of shares.

Some questions:
1) Will I have to pay capital gains to the US government or am I exempt under double taxation treaty if I pay UK capital gains?
2) If I do have to pay US capital gains, can I offset what I pay the US government against capital gains liabilities in the UK?
3) Since US and UK have different tax calendars, how to avoid double paying when the periods don't overlap?

Thanks for your help.

[AGoodman]

It looks like you may only have to pay in the UK - see the UK / US treaty Article 13(5).

BUT I have no clue about US tax so you need to check that, check you are UK treaty resident and how to claim the relief in the US.

[DavidTreitel]

The UK has the primary right to charge tax. Under the treaty, the US gives credit for UK tax paid each year. Consequently you'll want to be certain you pay the tax to HMRC by 31 December each year. The treaty has no effect because of the saving clause.

[JayCee2]

If I have a capital gain that was realised in august 2020, it would fall under the UK tax year April 2020 to April 2021, so it wouldn't be taxed in the UK until January 2022.
However for the purposes of US taxes it would have occurred in the period Jan 2020 to Dec 2020 so would have to be filed by April 2021.
Would this lead to a situation where I'd have to pay the full US tax because that is due first, and then later pay the full UK tax because they get "first claim".
Would I be able to offset the EXPECTED UK tax against any claim by the US government to avoid this situation?