Finding the Merchant Token in Seller Central:
From your seller account, go to the Settings menu and select Account Info.
In the Business Information section, select Merchant Token. The token is displayed at the bottom of the page.
Finding the Merchant Token without access to Seller Central:
If you do not have access to Seller Central you can find the merchant token of any Amazon Seller on Amazon by navigating to the individual seller.
Go to the Product Detail Page of a known ASIN of the seller.
Scroll until the Other Sellers on Amazon box appears.
3. Once in the storefront of the seller, the URL will show the Merchant ID as “Seller=”.