How do ShipStation shipments, cancellations, and voided labels sync with Endless, and why might a shipment be missing?

ShipStation notifies Endless when it ships an order, and background polling checks for missed shipments and later label voids. Use Get Shipment on the fulfillment order to fetch its history on demand, including older shipments and split orders.

When ShipStation splits an order into children, Endless verifies their relationship to the original order and records their shipments under the original fulfillment. Each distinct partial shipment keeps its quantities and tracking. An unclear match needs review rather than being assigned to an unrelated fulfillment.

Additional labels for exactly the same shipped items can add tracking numbers to one existing shipment without counting the quantities twice. If a voided label has one clearly matched replacement with the same items and quantities, Endless updates the existing shipment’s tracking. Its items and Shopify link stay in place. The linked Shopify fulfillment receives the tracking correction without another customer notification.

A voided label by itself does not cancel an Endless shipment. Ambiguous replacements or voids within groups of duplicate labels need review. If the goods did not ship, review the shipment, cancel it in Endless when appropriate, and correct the sales channel’s fulfillment too.

Polling retains failed lookups for retry while continuing with other shipments. Read the Timeline for lookup, matching, or recording errors. Get Shipment can help recover older missing shipments; contact Endless support if the match remains unclear.

Canceling or reverting a fulfillment sent to ShipStation asks ShipStation to delete its order. Confirm the result in the timeline and in ShipStation before resending. Cancel shipment in Endless does not void a ShipStation label; void the label in ShipStation.