In order to keep track of where your sales are coming from we provide separate carts, one for the marketplace and one for each custom store.
The marketplace checkout can only be accessed through the Storenvy marketplace. The custom store checkout can only be accessed from a custom store. This keeps it easy for our system to know where each sale came from, effectively separating Marketplace commissions from custom store orders. Additionally, your admin panel will clearly mark where each order you receive came from.