If my father pass away within 7 years, is the cash gift then liable to inheritance tax? Or does him being non-resident and non-domicile exempt the gift from inheritance tax regardless?
Here is the HMRC guidance [edited] on assets of non residents non domiciled in the UK:
'If you are domiciled abroad, inheritance tax applies only to your UK assets.'
As this cash gift was derived from moneys outside the UK taxation area then the Inheritance Tax rules for Potentially Exempt Transfers appear inapplicable, such moneys being outside the scope of UK taxation.
Apologies for the slight delay in response to your follow up question.