Marketplace Facilitator
Definition
A platform such as Amazon, Walmart or Etsy that is required to collect and remit sales tax on sales made through it. Your own website sales are still your responsibility.
Want a deeper explanation?
Marketplace facilitator laws mean the big platforms handle sales tax on orders placed through them. That is a relief, but it often gives sellers a false sense that sales tax is fully taken care of.
Your direct-to-consumer sales are not covered, and some states still expect you to register or file even when the marketplace collects. Watch for: a growing Shopify or wholesale channel in states where you only ever sold through Amazon.
Example
Amazon collects and remits tax on your Amazon orders, but your Shopify store sales into the same state may still require you to register.