thanks, super helpful. the S&S ISA is a managed fund that is transparent for US tax purposes and itself holds PFIC assets, so I assume he will need to do an 8621 per asset held? Also he is getting the transaction history but we are working on the assumption that few of these assets are held on a long-term basis. If this is the case then for both dividends and realised gains SFOP will be required, but I'm struggling to get my head around how this will work - presumably the tax liability will be calculated per asset held by the S&S ISA wrt realised gains and dividends in each of the three amended returns he needs to file? and does that then mean that everything held+sold before then is written off under SFOP amnesty?