Overview

In September 2023 Amazon expanded the Selling Partner API (SP‑API) by adding pack hierarchy support to the Listings Items API. The update lets sellers programmatically link individual units, case packs, and pallets within a single listing across the US, EU, and JP marketplaces. This capability improves inventory accuracy, boosts search visibility, and simplifies fulfillment for multi‑unit products.

Key Points

• Pack hierarchy attributes added to Listings Items API — Sellers can now declare unit, case, and pallet relationships in a single API call for the three major regions.
• Connected listings become possible — A single product can surface in search results for any linked package size, eliminating duplicate listings.
• Search visibility increases — Amazon’s matching engine can match customer queries to the appropriate package level, raising the likelihood of discovery.
• Inventory accuracy improves — The API records the exact number of units inside a case or pallet, reducing mis‑shipped orders and stock‑outs.
• Fulfillment flexibility expands — Sellers may offer individual and bulk purchasing options without creating separate listings, streamlining order handling.

How It Works

1. Define Pack Hierarchy — Include a packHierarchy object in the request that lists parent‑child relationships among units, cases, and pallets.
   Example: A 12‑piece case of a toy links to 12 single units, and a pallet contains 10 such cases.

2. Create Connected Listing — Submit a createListing call that references the hierarchy. Amazon treats the case and pallet as part of the same product family.
   Example: A shopper searching “toy set” sees the case pack, while a wholesaler searching “toy pallet” sees the pallet option.

3. Update Inventory and Pricing — Use updateInventory and updatePricing to set quantities and prices for each pack level. Amazon displays the correct price based on the selected package. Unit price $5, case price $48, pallet price $470.