Amazon actually has a useful page with good information for how to sell internationally on Amazon: https://services.amazon.com/global-selling/selling-internationally-overview.html/ref=asus_ags_snav_what The page on Regulations and Taxes.
You have probably heard of the Amazon Cart “999 Cart Trick” that can be used in qualifying sales of a potential competitor. It.
Generally, unless you intend to have employees, you do not need to get an EIN from the IRS website. EIN stands for “Employer Identification.