If you've connected multiple accounts for the same carrier, you've likely noticed the (Primary) indicator tacked on to one of your accounts. By default, ShipStation uses a Primary account for everything (like getting rates and shipping orders) unless another account is specified.
To ship an order with a carrier account other than the Primary one, follow these steps:
1. Go to the Orders tab on the toolbar, and select the Order # of the order for which you want to switch carriers.
2. Go to the Other Shipping Options section of the Order Details screen and select a different account from the Shipping Account drop-down menu.
3. If you don't see the Shipping Account drop-down menu on the Order Details screen, select a shipping service, then double-check that you have multiple accounts connected for the carrier's service.
While you can switch between your different accounts for a carrier while shipping an order, you cannot switch between your accounts everywhere in ShipStation. Some areas are only available for the Primary Account. These areas include (but aren't limited to):
Are you shipping with another account more than your primary? It's easy to make another account the Primary account.