Postby iwmtaxadvisor » Tue Feb 23, 2021 12:34 pm
US - UK tax planning is always complex and almost always requires specialist advice because of the myriad of 'gotchas' in the combined legislation. You cannot rely on any casual comment since it is more than possible you would not know what the relevant data is to disclose (no disrespect).
Given that,
UK IHT is charged on persons 'domiciled' in the UK. Domicile is a concept that is fuzzy (in both jurisdictions). But if you were an American national and you left the UK to go back to the USA then you would probably have abandoned your domicile of choice or your 'deemed domicile' in the UK upon leaving, from the UK's point of view. There is no statute of limitations. From the US point of view, you never lost your US 'domicile' as determined for estate duty. There might be grey areas here depending upon what you did, where you lived, how you got dual citizenship and much more: and if there are the UK US Estate and Gift Tax Treaty applies. As you probably know, the UK seeks to apply IHT to uk assets anyway.
There are about 100 UK-US tax specialists in the UK.