Teapplix ActionShip supports multiple warehouses. Multiple warehouse means your inventory quantity is divided among several warehouses. They could be internal warehouse, FBA warehouse, or external warehouse (3rd party).
You can ship orders from different warehouse with different ship from address.
You can track quantity across multiple warehouses, with separate quantity for each warehouse.
When you have multiple warehouses, you need to first enable multi-warehouse in ActionShip.
And you need to make sure the orders are set to the right warehouse for shipping and inventory tracking, listings are set the right warehouse for listing update.
Please refer to the following help docs for specific need: