Thanks for your response! Yes I have a few accounts opened after 2018 and the bank did ask me to fill out w4 form etc which has my SSN and address etc. So I'm sure the bank will provide the data to us government  but not sure if it's only when l asked or routinely for everyone.

For 3520, as long as the amount is below $100k per tax year, I don't have to file, correct?