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Enter your personal name, address and any info they ask
You can use your personal SS or business TAX ID (can change it later if you form a business later - it doesn’t matter for now). Amazon will send you a 1099 each year just like you are a commission-only sales contractor.
I used my sole-proprietorship tax info but your personal tax info is fine. You don’t need an LLC yet, until you are doing huge volume, because the tax differences on us are negligible, so don’t overthink it, unless you want an LLC to keep things organized or if you have a partner. We used myusacorporation.com to form an LLC for about $300 in Wyoming b/c JohnnyFD recommended it for ecommerce:)
It will take you thru a ‘tax interview’ - just enter all the info you can and follow the instructions. It shouldn’t take long.