Decide where you want to start based on your business’s current situation. Consider your product category, distribution rights, resources, and other factors. Many sellers have successfully launched immediately across all of Amazon’s North American stores. Amazon tools and services, like Build International Listings (BIL) and Fulfilment by Amazon (FBA) services in North America, make selling across all North American marketplaces much simpler.
Of course, if don’t want to sell across all three marketplaces yet, or if your distribution rights don’t cover all marketplaces, you can start with one or two of them.
With a North America account, you can easily switch between the selling tools of Amazon.com, Amazon.ca, and Amazon.com.mx in Seller Central to list products in multiple marketplaces and manage orders. You can list products in one, two, or all three available North American marketplaces. When managing your Amazon inventory across Amazon’s United States, Canada, and Mexico marketplaces, it is important to understand the difference between the Global SKU and the marketplace-specific SKU in Seller Central. You can find more information on these topics here