I am a dual citizen, both US and another country. Early this year I was requested by my stock broker (out side the US) to file either W8-BEN or W9 forms. As I was born outside the US and have never lived there, this US issue never came to concern me as I don't live/learn what's happening in the US with regards to there laws. So I filed W8-BEN form based on my local citizen and later on sold the stocks.
Now since I learn more about this US thing that I need to do tax reports (FATCA/FBAR/???) and other issues to fulfill obligations of being a US person (now I'm filling TAX reports to the IRS), I'm now worried that filling W8-BEN was a bad mistake.
So what should I do? re-submit form W9 or do nothing? If I re-submit W9 form as a US person then the broker will find two different forms. would I still be punished by the IRS or by some other body? Please advice, thank you