We are currently using ShipStation and once they switched over to the SP-API, there have been issues with processing orders that have multiple items/shipments.
We have to ship each item separately as our items are oversized and cannot be combined in a box. Before the SP-API switch, we were able to split our orders in ShipStation. This would integrate pretty well with Amazon Buy Shipping for the most part. For example, for one order with 10 items, we’d get 10 labels created and 10 tracking numbers in the Amazon interface/ShipStation.
Now with the SP-API, it’s glitching horribly. We’d get error messages in almost every batch. For example, out of two items in the same order, only ONE item successfully ships in ShipStation. The other one would result in an error and stay in “Awaiting Shipment”. But in the Amazon interface, it would show that the one label was created for BOTH of the items and they are both shipped under the same label.
Or sometimes one of them has shipped and the other hasn’t on both Amazon and ShipStation. But for some reason, we are unable to create a label for the unshipped item.
Another example: Sometimes Amazon does show that both items have shipped, separately, with their own tracking numbers… But it has not been carried over to ShipStation (one item remains “Awaiting Shipment”) while the specific label for the item that is “awaiting shipment” cannot be downloaded or voided off Amazon.
This is not something that happened at all with the old API.
ShipStation states: “Amazon’s new SP-API will not accept ShipStation shipment notifications for orders that are split or combined in ShipStation. At this time, you should not use the Split or Combine shipments feature for orders that import from Amazon Marketplace.”
There is no way in Amazon to process these quickly other than manually buying one label at a time through buy shipping for multiple orders.
We are curious if this is an issue with other shipping softwares because if this persists, we will have to switch to another software.