UK and US taxes on selling house

Hello

My husband is a USC, who is resident in UK. 
He is now in the process of selling his house in America this year, and we will be using the money to buy a house over here.
He will be paying capital gains tax in the U.S as he has not resided there for a number of years.
However, I am really confused about the UK tax system. 
When we move the money over (which will be a substantial amount), do we have to inform HRMC where the money came from?
If so, how do we do this?
Also, do we have to pay UK taxes as well, and them somehow claim them back?

I have been filing my husbands US taxes (using TaxAct) since he arrived here, and it has taken a lot of time and energy to get my head around the US tax system (which does not come naturally to me!)

I am wondering whether I should I contact a UK tax lawyer to help me with this?
UK Yankee were invaluable for helping me apply for my husbands visas, and I can't imagine that the UK tax system can be harder than that!
But for some reason I am feeling overwhelmed by it.

I would appreciate any help you can give me on this matter.

Thank you

Oh, and also, when does the USA tax the money from the house, is it straight away, or is it when we submit the tax return in April - June?

Your spouse will calculate the gain for UK purposes and pay UK tax on any such gain, after claiming credit for US tax payable on any doubly taxed gain.

This is almost double dutch to me.
I think I'm just going to see the advice of a UK/US tax solicitor.

Thank you for your reply though.

Guya’s accurate advice, in a more digestible way:

1. Husband pays his capital gains tax in the USA.

2.  Husband files his U.K. self assessment, declares the gain, then receives a credit for the amount already paid to the USA.

3.  If the USA tax was higher than the U.K. tax, no money owed to the U.K., meaning no additional tax due.

However if the U.K. tax owed is higher than the USA taxes paid, he will have to pay the difference between the two to the U.K.

It’s not technically “double” tax, as a credit is given for the USA tax. But it could be MORE tax.

4.  Definitely speak with a professional as they may have options that will put the money into a tax favourable position (for example gifting some of the gains). 

5.  Does he realise how UNBELIEVABLY LUCKY he is to have a wife who has learned US taxes?!?!? 

Thank you KFDancer  :-)
Using your info I was able to have a good look on the internet last night.
Looking at CG tax in the USA and UK at midnight, does not help for a good nights sleep!

However this has helped give me a much clearer view, so thank you!

Am I right in thinking that my husband reports the sale of his house when he (I) file his taxes.
So if we sell the house in April 2022
Its reported as part of his IRS tax return next year, and any Capital Gains paid

My (hopefully last) question is, when would we file with HRMC, as I won't know what Capital Gains that are due to the IRS and have to be paid, until we file next year.
Or, would I have to work it out before filing in USA and still file the self assessment with HRMC this year?

Thank you again
Gaby

5.  Does he realise how UNBELIEVABLY LUCKY he is to have a wife who has learned US taxes?!?!? 

He should do, I tell him often enough  :-D

Thank you KFDancer  :-)
Using your info I was able to have a good look on the internet last night.
Looking at CG tax in the USA and UK at midnight, does not help for a good nights sleep!

However this has helped give me a much clearer view, so thank you!

Am I right in thinking that my husband reports the sale of his house when he (I) file his taxes.
So if we sell the house in April 2022
Its reported as part of his IRS tax return next year, and any Capital Gains paid

My (hopefully last) question is, when would we file with HRMC, as I won't know what Capital Gains that are due to the IRS and have to be paid, until we file next year.
Or, would I have to work it out before filing in USA and still file the self assessment with HRMC this year?

Thank you again
Gaby

He should do, I tell him often enough  :-D

If he sold his house after April 5th 2022 then it will be reported on his HMRC 22/23 tax return which is not due until January 2024 so he will know how much US tax he has paid by then

Thank you Durhamlad!

It is such a strange concept to wrap  my head around that I don't immediately have to report/file to two government tax bodies that we have sold a house/moved a large amount of money to the UK.

I was previously under the impression (having never had done it) that everything would have to be reported straight away.

Yet another lesson learned.
As well as now knowing what Capital Gains, Cost Basis and Adjusted Basis all mean!

Thanks again everyone :-)