Does ShipStation charge me for my postage?

No. Your postage provider charges you for the labels you create in ShipStation. ShipStation does not collect your label fees.

For labels using ShipStation Carrier Services, Stamps.com is the postage provider. When creating a Stamps.com account in ShipStation, or using ShipStation Carrier Services, you'll be prompted to enter the credit card to use for your label fees.