Overview

Amazon has lifted the request ceiling on several Fulfillment Inbound API calls from two to five per second, a 150 % jump that activates automatically for both the current v2024‑03‑20 specification and the legacy v0 version. The change removes a long‑standing throttling bottleneck for sellers and developers who automate FBA inbound workflows, and it requires no code modifications.

Key Points

• Rate ceiling raised — The affected endpoints now accept five calls each second, up from two, equating to roughly 18,000 requests per hour when used continuously.
• Both API generations covered — The increase applies to the newest v2024‑03‑20 API as well as the older v0 version, so sellers who have not yet migrated still receive the benefit.
• Zero‑touch deployment — Amazon implemented the new limits on its servers; developers do not need to re‑authorize, adjust settings, or rewrite integration code.
• Core inbound endpoints upgraded — The getShipment, listShipmentBoxes, listDeliveryWindows, listTransportationOptions, and getShipmentOperation operations all enjoy the higher throughput.
• High‑volume users stand to gain most — Sellers handling hundreds to thousands of inbound shipments daily will notice a sharp reduction in throttling errors and latency.

How the Fulfillment Inbound Rate Limit Upgrade Works

1. Request handling window — When a client sends a request to any of the upgraded endpoints, Amazon now permits up to five calls within any one‑second interval.

   • Example: A software tool that previously paced calls at 2 rps can now issue five calls in the same second, allowing three additional queries without triggering a 429 error.

2. Server‑side throttling logic — Amazon’s gateway monitors the per‑second count; once the five‑request threshold is reached, further calls are delayed until the next second begins.

   • Example: If a seller submits five listShipmentBoxes requests at 00:00.200, a sixth request at 00:00.250 will be held back and processed at 00:01.000.