Amazon ends its commingling practices across its Fulfillment by Amazon supply chain on March 31, 2026, closing a chapter on an inventory pooling system that has drawn complaints from brand owners for years. The policy, announced on Amazon Seller Central forums roughly four months ago, draws a sharp operational line between brand owners enrolled in Amazon Brand Registry and the broader population of marketplace resellers.

The change is not a minor logistics adjustment. It restructures how inventory ownership, returns, and accountability work inside Amazon's fulfillment network - and it arrives at a moment when the company has been systematically tightening its operational policies across multiple fronts.

What commingling actually is

Commingling - the practice at the centre of this change - refers to the way Amazon fulfilled customer orders. When multiple sellers listed the same product using a shared manufacturer barcode such as a UPC or EAN, Amazon pooled their inventory together across its fulfillment centers. A customer ordering a given product might receive a unit from any seller who had stocked that ASIN, regardless of who they actually bought from.

According to Amazon's official announcement posted on Seller Central, the rationale was speed: "Commingling is when we fulfill customer orders using exact product matches from the closest available inventory in the Amazon fulfillment network, even if that inventory belonged to a different seller, to achieve faster delivery speeds."

The system had a practical logic in its early years. With sellers distributed unevenly across geographic regions, pooling inventory allowed Amazon to ship from the nearest available unit without routing orders across the country. But the tradeoff was accountability. Under commingled conditions, there was no reliable way to determine which seller's physical unit reached a given customer.

The counterfeit and quality problem

For brand owners, the consequences of commingling were often concrete and costly. A product sourced from an unauthorized or low-quality reseller could end up fulfilling an order placed through the official brand's listing. Counterfeit units, expired products, or items with damaged packaging entered the fulfillment pool and were indistinguishable from genuine stock. Negative reviews and customer complaints followed - attached to the brand, not to the seller whose unit caused the problem.

The only way brand owners could opt out was to pay for FNSKU stickers on every unit shipped to FBA. These Fulfillment Network Stock Keeping Units - Amazon-specific barcodes that override manufacturer barcodes - ensured a seller's inventory stayed segregated within the fulfillment network. That meant an extra labeling cost on every single inbound shipment, just to maintain basic traceability over one's own products.

As Liran Hirschkorn, CEO and founder of IncrementumDigital.com, noted in a LinkedIn post: "Brand owners have been paying to re-label every unit with FNSKU stickers just to opt out of commingling. That's extra cost on every single shipment to FBA, just to make sure YOUR inventory stays YOUR inventory."

Today, that workaround becomes the default - and the cost becomes unnecessary for qualifying brand owners.

How the new rules work

Amazon's announcement breaks the new framework down by seller type. The distinction is binary and determined by a seller's status within Amazon Brand Registry.

Brand owners holding the Brand Representative selling role in Amazon Brand Registry no longer need to apply Amazon barcode stickers to prevent commingling on products that already carry valid manufacturer barcodes - UPC, ISBN, EAN, or JAN. According to the official Amazon announcement, "This means more flexibility in how you manage inventory because you will not need to pre-allocate units to Amazon or other channels."

There is one critical caveat: products must have valid GTINs (Global Trade Item Numbers). Sellers with GTIN exemptions still need Amazon barcode stickers. The benefit applies specifically to products with properly registered manufacturer barcodes in the GS1 standard.

Resellers - defined as sellers not enrolled in Amazon Brand Registry with a Brand Representative role - must now apply Amazon barcode stickers to every unit, without exception. This applies even to authorized resellers. Even where a brand owner has granted permission to sell their products, the reseller must still apply FNSKU labels after March 31. According to Amazon's forum post, "if you are already using these stickers, you can continue to follow your existing process" - meaning compliant resellers face no disruption. Those who were relying on manufacturer barcodes face the most significant adjustment.

For products that have no manufacturer barcode at all, both brand owners and resellers must continue using Amazon barcode stickers. This category is unaffected by the commingling change.

What happens to existing FBA inventory

A question that generated significant discussion in the Amazon Seller Central forums concerned existing inventory already inside fulfillment centers. The answer, according to the announcement, is that no retroactive action is required. Inventory already held in FBA warehouses is grandfathered under the previous system. The new requirements apply only to new shipments sent to fulfillment centers on or after March 31, 2026.

One seller forum participant, posting under the handle Seller_kK1QAXIbpanK7, asked directly: "Just to clarify, sellers can continue to send in manufacturer barcode/commingled up until March 31st? Also what happens after March 31st with the leftover commingled inventory that's already there?" The thread generated follow-up responses from Amazon moderators confirming the grandfathering approach.

Amazon is also waiving low-inventory-level fees during the transition period, according to the Liran Hirschkorn LinkedIn analysis. This provides some buffer for sellers depleting old SKUs labeled under previous practices while building new stickered inventory to replace it.

The defective unit classification, however, applies immediately for non-compliant new shipments. Units arriving at fulfillment centers without required barcodes after March 31 will be flagged as defective. Defective units are not eligible for reimbursement under Amazon's FBA policies, a significant financial consequence for resellers who miss the compliance window.

Operational consequences for different seller types

The divergence in requirements creates meaningfully different operational realities depending on where a seller sits in the supply chain.

For direct-to-consumer brands and manufacturers enrolled in Brand Registry, the March 31 change is largely a cost reduction. The ongoing expense of FNSKU labeling on every inbound shipment is eliminated for qualifying products. Supply chain flexibility improves as well - without the need to pre-allocate inventory between Amazon and other sales channels, brands can manage unified stock pools more efficiently.

Returns and removals are now routed back to the specific seller's inventory, not pulled from the general commingled pool. This matters significantly for accountability. Under the old system, a brand processing a removal order might receive units that were never theirs to begin with. Going forward, what comes back is what went in.

For resellers, the operational burden increases. Wholesale sellers who were sourcing products from authorized distributors and shipping them to FBA without additional labeling must now integrate barcode printing and FNSKU label application into every inbound shipment. The physical formatting requirements are specific: printed labels must match the Seller Central generated format exactly, with 0.25 inch of white space on sides and 0.125 inch on top and bottom surrounding both the barcode and label content edges. The ASIN or FNSKU identifier must appear alongside the product name and item condition.

As PPC Land reported in February 2026, resellers who operate retail arbitrage models and already apply Amazon labels will experience the least disruption - the policy effectively codifies existing practices. Wholesale resellers maintaining authorized distributor relationships face the more significant adjustments.

The broader enforcement context

Amazon's announcement acknowledges that the operational rationale for commingling has eroded. According to the Seller Central post, "Now that most sellers maintain inventory levels that keep products close to customers, we can achieve fast delivery without commingling." The network has matured to the point where geographic distribution is sufficient for delivery speed without pooling inventory from different sources.

But the timing and design of the policy suggest additional motivations. Hirschkorn characterized it plainly: "This is Amazon tightening the noose on gray market sellers." The reference to Bath & Body Works launching their own Amazon storefront to reclaim approximately $80 million in unauthorized sales captures the context. Brand owners have been losing revenue and brand equity to unauthorized sellers operating within Amazon's ecosystem, and the commingling system gave those sellers cover.

Amazon's counterfeit crackdown has been escalating for several years. The company's Counterfeit Crimes Unit had initiated legal action or criminal referrals against over 21,000 bad actors since its 2020 launch, according to a 2024 Brand Protection Report. Advanced seller vetting technology including document forgery detection and AI-powered analysis stopped over 700,000 bad actors from creating selling accounts in 2023 alone. The commingling change fits within this wider pattern of supply chain enforcement.

The policy also intersects with Amazon's FBA damaged inventory ownership changes that took effect March 31, 2025 - exactly one year earlier. That policy shifted responsibility for damaged inventory from the platform to sellers. Today's commingling change shifts accountability for physical product identity from the collective pool to individual sellers. Taken together, the direction is consistent: Amazon is building a supply chain architecture where every unit is traceable to a specific seller, with consequences attached to that seller specifically.

Seller community reactions

The Seller Central forum post accumulated 1,900 views and 64 replies, reflecting the scale of interest. Reactions ranged from relief to frustration, largely depending on seller type.

One early responder, posting under Seller_TeK7HYTK7PiOb, wrote simply: "About time. Hopefully this will help with some of the counterfeiting problems or used sold as new complaints."

Andrea Ram, CEO of SelegnaPath, characterized the change in structural terms in a LinkedIn comment on the Hirschkorn post: "This is a structural shift in control, not just a logistics update. Separating inventory closes one of the biggest gaps that allowed counterfeit and gray-market leakage to go undetected. Now, enforcement has a cleaner foundation because ownership and accountability are no longer blurred."

Ivan Raineri, commenting on the same thread, highlighted the implications for return dispute resolution: "The shift to seller-specific return will change how reimbursement disputes get resolved. With commingled inventory, tracing a mis-processed or lost return to the correct seller was basically impossible. With returns now routed back to your specific inventory, the traceability is improved."

Not all reactions were positive. A seller posting under Seller_3qllv6SY8mdjV raised the cost burden: "This is super wasteful. I will now have to label thousands of products by hand costing lots of $ and time for that labor." The post also noted that Amazon had recently removed its prep service, meaning sellers cannot pay Amazon to apply labels on their behalf. Another forum participant, Seller_9W2kRFvevaGCQ, made a longer argument for preserving commingling access for resellers with the "Reseller" role within Brand Registry, noting the environmental cost of paper labels and plastic backing material at scale.

The tension between brand owners and resellers that emerges in these responses reflects a long-standing structural conflict within Amazon's marketplace. Brand owners want control over the customer experience attached to their products. Resellers - including fully authorized ones - face increasing compliance costs that make thin-margin arbitrage models harder to sustain.

Implications for the marketing and advertising community

For the marketing and advertising community, the March 31 change carries implications that extend beyond fulfillment logistics. Brand integrity on Amazon is directly tied to listing performance, review scores, and advertising effectiveness.

Sponsored Products and Sponsored Brands campaigns draw on organic listing performance as a baseline. When commingled units from unauthorized sources generated negative reviews on a brand's listing, those reviews suppressed the listing's conversion rate - and with it, the efficiency of advertising spend. A brand running a Sponsored Products campaign against a listing damaged by counterfeit-related reviews was, in effect, paying to drive traffic to a compromised destination.

Amazon's reserve share of voice feature for Sponsored Brands, launched in October 2025, allows brands to secure top-of-search placements for branded keywords at fixed prices. The value of that placement depends heavily on the quality and trustworthiness of the landing listing. Stronger supply chain controls reinforce the investment in branded search advertising.

The commingling change also affects how brands structure their multi-channel inventory strategies. Without the need to pre-allocate units to Amazon, brands can maintain unified inventory pools across channels, reducing the risk of stockouts in any single channel and improving capital efficiency. For marketing operations that depend on consistent product availability to run continuous advertising campaigns, this flexibility has real value.

What the GTIN requirement means in practice

One technical detail deserves closer attention. The brand owner exemption from FNSKU labeling requires "valid GTINs" - Global Trade Item Numbers assigned through GS1, the international standards organization that manages product identification codes. UPCs, EANs, ISBNs, and JAN codes are all GS1 standard identifiers.

Sellers who received GTIN exemptions from Amazon - a common accommodation for certain product categories or custom bundles - do not qualify for the manufacturer barcode pathway under the new rules. They must continue using Amazon barcode stickers regardless of Brand Registry status.

This creates a practical distinction within the Brand Representative category itself. A brand owner with full GS1-registered barcodes on all products gains maximum flexibility from the March 31 change. A brand owner who obtained GTIN exemptions for some or all of their catalog sees no change in labeling requirements for those products.

The forum thread surfaced this complexity. One seller, posting under Seller_QeFe6GpYlfyoK, described a specific scenario: a single UPC assigned to multiple ASINs, asking whether the new changes would address that situation. The concern reflected a real-world complication where manufacturer barcode eligibility may be product-by-product rather than account-wide.

Policy fits within a broader Amazon restructuring

The March 31 commingling policy does not sit in isolation. Amazon has restructured multiple dimensions of its FBA operating rules over the past 18 months.

The removal of partial shipment splits for standard-size products took effect February 20, 2025, changing how sellers distribute inventory across fulfillment centers. The FBA damaged inventory ownership program took effect March 31, 2025, shifting liability for damaged units. Per-unit billing for FBA removals changed payment timing starting February 15, 2026. Mandatory prepaid return labels for all US seller-fulfilled orders took effect February 8, 2026. And Amazon's Business Solutions Agreement update introduced formal AI agent compliance requirements effective March 4, 2026.

Each change, viewed in sequence, points in the same direction: more granular seller accountability, more defined cost allocation, and more structured distinction between different types of marketplace participants. The commingling end is the most operationally significant of these changes for sellers who have relied on the pooled inventory system.

Timeline

Summary

Who: Amazon, its FBA brand owner sellers enrolled in Amazon Brand Registry with Brand Representative roles, and all marketplace resellers using Fulfillment by Amazon services.

What: Amazon ends its commingling inventory practices, which pooled products from multiple sellers sharing the same manufacturer barcode within fulfillment centers. Brand owners with valid GTINs and Brand Representative status are no longer required to apply FNSKU stickers to prevent commingling. Resellers, including authorized ones, are now required to apply Amazon barcode stickers (FNSKUs) to every unit sent to FBA, with non-compliant units classified as defective and ineligible for reimbursement. Returns and removals now come exclusively from the specific seller's inventory rather than the general commingled pool.

When: The policy change was announced on Amazon Seller Central forums approximately four months before implementation - in late November 2025. It takes effect on March 31, 2026, for all inventory shipped to Amazon fulfillment centers on or after that date. Inventory already held inside FBA warehouses is grandfathered and requires no action.

Where: The change applies across Amazon's US fulfillment network and affects all sellers using Fulfillment by Amazon services in the United States marketplace. The policy is managed through Amazon Seller Central and Amazon Brand Registry.

Why: Amazon states that its fulfillment network has matured to the point where most sellers maintain sufficient inventory distribution across fulfillment centers to achieve fast delivery speeds without pooling inventory from different sellers. Beyond the stated operational rationale, the policy responds to persistent problems with counterfeit products, expired goods, and gray-market inventory entering the fulfillment pool through commingling - problems that brand owners have documented for years and that Amazon's Counterfeit Crimes Unit has been escalating enforcement against since 2020.

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