Overview

Amazon released a June update to the Fulfillment Inbound API (version 2024‑03‑20). The upgrade introduces three core functions—delivery‑window selection, item‑level label creation, and partnered‑carrier designation—that directly affect how sellers schedule and ship inventory to Amazon fulfillment centers. Understanding these changes is essential for maintaining a steady inbound flow and avoiding avoidable processing errors.

Key Points

• Delivery‑window visibility — Sellers can now request a list of specific inbound time slots for a chosen fulfillment center and pick the one that aligns with their warehouse staffing.
• Item‑level label generation — The API accepts calls that produce individual labels for each SKU, making mixed‑case shipments easier to label accurately.
• Partnered‑carrier option — When a shipment is created, sellers may indicate “Partnered” as the carrier mode, allowing Amazon’s logistics network to handle transportation.
• Optional parameters — All new fields are additive; existing calls continue to work unchanged unless the seller opts into the new capabilities.
• Enhanced error codes — Responses now include distinct codes such as InvalidWindowId and UnsupportedCarrier, giving developers clearer guidance on why a request failed.

How the Updated Fulfillment Inbound API Works

1. Retrieve delivery windows —

   • Issue a GET /inbound/deliveryWindows request, supplying the destination fulfillment center identifier.
   • The service returns a catalog of slots, for example “Monday 08:00‑12:00” or “Thursday 15:00‑19:00”, each paired with a unique windowId.
   • Example: A seller planning to send 750 units to the Dallas fulfillment hub (DFW1) receives three available windows and selects the Thursday 15:00‑19:00 slot because their dock crew is scheduled for overtime that day.

2. Create a shipment with a chosen window and partnered carrier —