How to send email to IRS and US treasury to complain about the 10% PTPs tax?

The type of form you mail in depends on how you recognized yourself at the time of initiated transaction but it’ll be one of three to start with ;
Form 1120-F

Form 1040-NR

Form W-8BEN

 

I filed the W-8BEN form when I opened my account which I should renew every three years

 

if you have day trader status through an entity you’ll file a Form W-8EC

If it’s a sole prop, “usually” it’s a W-8BEN

but it’s all circumstantial