Short answer: Amazon splits FBA shipments to place inventory across its network. You cannot turn splits off, but you choose a placement option: Amazon-optimized splits (several destinations, no fee) or minimal splits (usually one destination, for a per-unit inbound placement fee). Identical boxes, more boxes and keeping standard, oversize and special handling items in separate plans give you more options.

Split shipments have always been frustrating for new sellers. Amazon splits inbound inventory to place it closer to customers, which it says lets it deliver faster at lower cost. In this article, I cover what Amazon currently publishes about splits and how to work with the placement options it gives you.

One change matters before anything else. Amazon now charges an FBA inbound placement service fee on standard-size and bulky-size products (extra-large products carry no placement fee). When you build a shipping plan you choose one of three placement options: Amazon-optimized shipment splits (inventory goes to several locations, usually five or more, no fee), partial shipment splits (two or three locations, reduced fee, available only for bulky-size products, not standard-size), or minimal shipment splits (generally a single location, for a fee). Amazon publishes the current per-unit fee tables on a Seller Central help page, so check it before you decide that a single-location shipment is cheaper. Since January 15, 2026, Amazon also charges an inbound defect fee on shipments that are misrouted, deleted, abandoned or incomplete, so do not create shipping plans you do not intend to send.

How we decide at Marketplace Prep: shipments of about five pallets or more almost always go out as Amazon-optimized splits, because each destination still gets a full pallet or more. Very small shipments go small parcel. Everything in between is a judgment call based on pallet weight, cubic volume and box count. Either way, Amazon decides which fulfillment centers your inventory ends up in, based on where it sells.

1. Know your barcode type

When adding SKUs in Seller Central, a brand owner with the Brand Representative role in Brand Registry can use the manufacturer barcode (UPC, EAN, ISBN). Resellers must use an Amazon barcode, a custom FNSKU (Fulfillment Network Stock Keeping Unit) label. Amazon ended commingling for inventory shipped on or after March 31, 2026.

Amazon’s published list of factors that decide how a shipment is split does not include barcode type. It names the mix of standard-size, non-standard-size and special handling items, the item mix in each box, quantities and number of boxes, and regional demand. Labeling is still worth getting right, but treat it as a receiving requirement, not a way to prevent splits.

2. Case Packing vs Individual Units

Amazon says that keeping the same SKU mix and quantity in every box, and increasing the number of boxes, improves your chances of qualifying for Amazon-optimized splits. Identical case packed boxes fit that guidance. Whether a given case pack setup splits differently from individual units is something Amazon does not publish, so test it on your own shipments, because each business will find different use cases for “Case Packed” vs “Individual Units”.

3. Specialty Categories

One of the more well-known reasons items split is product type. Amazon’s guidance is to create separate shipments for standard-size items, for non-standard-size items, and for each special handling category, because the right destination depends on what the facility can handle. Categories sellers commonly see handled separately include:

Oversize
Specialty Oversize (unusually large or heavy)
Hazmat
Other special handling categories shown in your shipping plan

Stocking in these categories means it is harder to build up larger shipments, because each category is planned on its own.

4. Shipment Upload Type

How you build your shipping plan affects what options you see. Send to Amazon, and the Fulfillment Inbound API version 2024-03-20 behind it, work in steps: you set packing information, Amazon returns pack groups (groups of SKUs that can be packed together), then it generates placement options and you confirm one. Adding items one at a time or in a batch file changes what goes into each plan, so keep plans organized by size tier and special handling category. Software can speed up the prep side, and you can also do this directly in Seller Central.

5. Quantity

For years sellers talked about an “18 unit rule”: ship at least 18 units of a SKU and Amazon would not split it. Amazon does not publish that threshold, and sellers have reported it stopped holding. What Amazon does say is that quantities per item, the number of boxes and regional demand all affect which placement options you qualify for. Larger, more uniform shipments generally have more options, but there is no unit count that guarantees a single destination.

6. Book Non-Partnered Carrier Freight

This one will not be applicable to everyone. If you ship LTL or full truckload freight, you can use a carrier other than Amazon’s Partnered Carrier program and compare quotes. Amazon’s guidance for non-partnered carriers is that you or your carrier must schedule a delivery appointment with the fulfillment center, which is not done automatically as it is with partnered carriers, and that the carrier should be registered with Amazon Carrier Central. Carrier Central is Amazon’s appointment scheduling portal. Whether a non-partnered carrier is cheaper depends on your lane and freight, so get both quotes.

Want fewer splits without the guesswork? Marketplace Prep builds and ships FBA shipment plans every day. Schedule a call or browse our FBA prep guides.

Sources

Amazon Seller Central help pages require a seller login.

Amazon FBA Split Shipments: 6 Ways to Save on Inbound Shipping Costs