Overview

Amazon has integrated the United States Postal Service’s Ground Advantage service into its Buy Shipping catalog, making it selectable through both the Merchant Fulfillment API v0 and the Shipping API v2. The update is live immediately, while the older USPS First‑Class Package options will be removed from the system on October 31 2023. Sellers who generate shipping labels via Amazon must understand the new offering, its cost model, and the integration changes required before the deadline.

Key Points

• Service now live — Ground Advantage appears in the Buy Shipping list for all qualified sellers today, reachable with the same API calls used for other USPS choices.
• First‑Class sunset — All First‑Class Package methods are automatically disabled on 31 Oct 2023; any order still referencing those codes will fail label creation.
• Unified rate structure — Ground Advantage consolidates the pricing of several former USPS products (First‑Class, Priority Mail, Priority Mail Express) into a single, weight‑based or flat‑rate figure.
• Weight coverage — The new carrier accepts parcels from 0.1 lb up to 70 lb, spanning the full spectrum that previously required multiple service selections.
• Transit estimate — Amazon advertises a 2‑5 business‑day delivery window for Ground Advantage, mirroring the typical timeline of the retired First‑Class service for light shipments.
• API compatibility — The feature is exposed in both the legacy Merchant Fulfillment API v0 and the newer Shipping API v2, allowing existing integrations to continue with minimal code changes.

How USPS Ground Advantage Works

1. Identify the carrier — Call GetEligibleShippingServices (or the v2 counterpart) and look for the USPS_GROUND_ADVANTAGE entry in the response.

   • Example: A seller requesting options for a 0.5 lb package destined for ZIP 30301 receives Ground Advantage alongside UPS Ground and FedEx Ground.