If you have multiple storefronts on different e-commerce platforms (for example, a Shopify store and an Etsy store), then you can connect both of those to one Shippo account.
However, if you have multiple stores on a single e-commerce platform (for example, two Shopify storefronts), you will only be able to connect one of them to your Shippo account.
To get around this, you can either create two Shippo accounts or import your orders from your second store into Shippo via a CSV file.
The only exceptions to this is our integration with eBay and Amazon. Shippo does allow for multiple eBay/Amazon stores to be connected to a single Shippo account. You can read more about that for eBay here, and for Amazon here.