US Estate Tax for Non-resident and Non-Domiciled deceased?

Trusts Discussion
1

The deceased is a UK domicile with very significant investments and cash deposits in several overseas jurisdictions.

I am struggling to decipher the US asset-situs rules in relation to his cash deposits of USD and investment portfolios, etc held in USD (some US corporations but not all) but held outside the USA by non-US banks and institutions including in Cayman, Singapore and Jersey

Can anyone direct me to any ‘relatively simple’ articles or similar that will assist us in ascertaining whether a US estate report is required and whether we need specialist advice in relation to any of the assets?

Many thanks

2

Not sure, but there is a US-UK double tax treaty for IHT which (generally speaking) gives exclusivity to the jurisdiction of domicile?