So today by damn chance i found out there's a form to fill for non US residents "W-8BEN".
If you don't fill it, Google will withhold 30% of your earnings.
So for years I didn't fill this form.
I wonder if the money is for them to keep, or would they refund it to me? (i guess not)
I assumed something this vital would merit a BIG RED warning banner at the top of the Adsense page but nah.
I bet there are thousands of accounts who are paying taxes twice as me and nobody warns them.