Do I use the Orders or Shipment object to purchase labels?
You could use the Orders object exclusively instead of creating a Shipment object, but it's not recommended for a few reasons.
- Shipment options and customs information must be specified using the Shipment object, not the Orders object.
- UPS will tie all of their rates and trackers to the first Shipment in the Order. It'll be difficult to glean tracking and rate information from UPS without creating a Shipment.
- EasyPost Insurance is handled on the Shipment level, not the Order level.