Updated
It depends on your plan, and on whose carrier account the label is bought against.
To get a shipping label, you can use one of ShipStation’s carrier accounts where they offer you negotiated discounts. You can read what those discounted rates cover. If you use these, you pay ShipStation for the label.
Or, you can connect your own carrier account to get shipping labels. If you use your own account, you’ll be billed for shipping labels by your carrier.
Connecting your own accounts carries its own cost. ShipStation documents a monthly fee for the Your Carriers add-on, which is what allows you to connect and ship with your own carrier accounts, and states it varies by plan.
On some plans there is also a per-shipment fee for labels created against your own carrier accounts, and it varies by plan and country — ShipStation publishes the schedule. In the US and Canada it applies on High Volume plans; UK, EU and ANZ accounts pay it on a per-plan scale. Check the current figure for your own plan before doing the arithmetic. You can learn more about that fee here.
Between the add-on and the per-shipment fee, it can be hard to work out whether your own account or ShipStation’s is cheaper for a given shipment. It is usually the wrong question: connect both and let a rate comparison pick per order, because narrowing to one carrier costs more than it saves.
If you want to work out which account is actually cheaper once the fees are included, the self assessment does the arithmetic from two ShipStation exports.
Knowing how a carrier prices a parcel is useful. The harder question is which parcel to make — because the packing decision sets the dimensional weight and the cubic tier, and the cheapest box changes with the contents, the destination and the rate card.
There are eight situations where that decision has grown past what a rule can express. Most operations are in two or three of them.
