This is also what my accountant thinks...she doesn't think that cash ISAs or even share ISAs require this form, thank goodness. I also know that some argue that personal pension schemes could be arguably foreign grantor trusts but, again, my accountant is invoking the UK/US tax treaty that allows for tax-free growth in pension funds. My financial planner recommended that I consolidate my personal pension into my new employer's pension scheme that my employer opened up for me earlier this year.


The investment ISAs still had foreign tax credits for the dividends whereas the Cash ISAs showed no tax credit so were fully taxable to the IRS.

I should imagine that even in a worst case scenario, were the IRS to question why I didn't submit these 3520/3520A forms that I could argue reasonable cause, especially as I had a specialized accountant deal with my returns.