US domiciled ETFs - without the KIIDs?

Correct - I meant they need they need to be UK-Reporting ( I think) to be ISA compliant. Youā€™ll notice ā€œISA Compliantā€ and ā€œSIPP Compliantā€ on a lot of ETF factsheets for UK customers. Iā€™m assuming (and have noticed its true on any Iā€™ve looked at) that UK reporting = ISA compliant.

You are of course free to buy non-UK reporting in GIA, and deal with the bigger tax bill.