Your merchant token is a
unique seller identifier used in Amazon Merchant Transport Utility (AMTU), third-party
applications, and XML feeds to match up products that you upload with your seller
account.
Note: You cannot share a merchant token with other
sellers or use it for different seller accounts. It is unique to a given seller.
View your merchant token
Note: The View your merchant token steps mentioned above is only available for Selling Partners enrolled in the Professional Selling Plan.