US capital gains, pay HMRC or IRS first

Hi,

I made a profit on some shares held in a US brokerage, sold just before the UK raised CGT in October. I'm dual citizen and live in the UK full time. My question, who do I pay first, HMRC or IR?

I had just assumed that I would pay my US 2024 income tax, and then when I come to do my UK self assessment, report my gain and claim the 10% I have already paid IRS, reducing my UK CGT by roughly 10%. But I got reading the treaty a bit more closely, and maybe I need to pay HMRC the full 20% and claim the credit on my US filing, but as it is a US brokerage, presumably henge submitted the 1099 to the IRS.

Any thought or advice, most welcome!

The UK has the primary right to charge tax. The 2024 US return will claim credit for tax paid to HMRC by 31 December 2024.

Thanks Guya. Assuming I paid the UK CGT before Dec 31, 2024 (I didn't) what would the IRS return look like? Would you just omit the gains on the US return and explain the situation on form 8833 citing the appropriate treaty clause?

Now, as I didn't actually pay the CGT by the end of 2024, I guess there will be multiple years of claiming something somewhere and claiming it back somewhere else...