Amazon Seller News 2026: SFP Crackdown, FBA Fee Hikes & Buy Box Overhaul

Amazon sellers entering the 2026 holiday season are confronting an unprecedented convergence of policy changes, algorithm updates, and regulatory pressures. Over the past two months, the company has instituted aggressive performance audits for its Seller Fulfilled Prime (SFP) program, restructured Fulfillment by Amazon (FBA) fees, allegedly opened a data pipeline for its private-label division through Project Nile, and rewritten the Buy Box algorithm without public documentation. This article breaks down each development, what it means for sellers, and how to navigate the shifting landscape.

What Is Amazon’s New Seller Fulfilled Prime Crackdown?

The key change is a quietly enforced performance threshold: Amazon now requires SFP sellers to maintain a 93.5% same-day ship rate over any rolling 30-day period. According to ecommerce-times.com, this undisclosed standard caught many established sellers off guard. When a seller falls below the threshold, they receive a probation notice and have a 10-day window to cure the deficiency. Failure to do so results in a 60-day suspension from the SFP program, which effectively kills the seller’s ability to offer Prime badges on their own fulfilled products — a critical feature for Q4 sales.

Large merchants that have built multi-million-dollar alliances around SFP are scrambling to adjust. The suspension coincides with the peak shopping season, threatening revenue for sellers who relied on SFP to win the Buy Box. Many are now forced to either improve their fulfillment speed or shift to FBA. Amazon has not publicly announced this metric, leaving sellers to discover it only after being placed on probation.

How Do the New FBA Fee Tiers Affect Seller Margins?

Effective August 1, 2026, Amazon introduced its latest round of FBA fee adjustments. The most notable addition is the “Large Bulky Plus” tier, which applies to oversized items that previously fell into lower categories. According to ecommerce-times.com, the changes also include increased per-unit fulfillment fees for standard-size items priced under $12, and a new “low-inventory surcharge” that penalizes sellers who maintain thin stock levels.

Fee Change	Impact	Effective Date
Large Bulky Plus tier	Higher fees for oversized items	August 1, 2026
Per-unit fee increase for items under $12	Squeezes margins on low-cost goods	August 1, 2026
Low-inventory surcharge	Penalizes sellers with inconsistent stock levels	August 1, 2026

These changes are forcing sellers to reprice products or risk losing the Buy Box. Some sellers are switching to Fulfillment by Merchant (FBM) to avoid the fees, but FBM historically has lower Buy Box win rates. The article notes that many sellers are now actively considering diversifying to other platforms such as Walmart Marketplace. The fee restructuring comes at a time when sellers are already dealing with higher advertising costs and increased competition from Amazon’s own brands.

What Is Project Nile and Why Are Sellers Alarmed?

Project Nile is a leaked internal program that, according to reports, grants Amazon’s private-label division early access to aggregate seller performance data in high-margin categories. As detailed by ecommerce-times.com, the alleged practice would allow Amazon to identify which products are selling well and at what margins before launching its own competing items. Amazon has denied using individual seller data, but the leak has stirred deep distrust among third-party sellers.

The controversy has fractured seller advocacy groups. Some are pushing for formal complaints to regulators, while others want a more confrontational public campaign. The core issue is competitive fairness: if Amazon can use aggregated data from tens of thousands of sellers to inform its own product development, smaller sellers fear they are being systematically squeezed out of profitable niches. No official confirmation has been provided, but the leak alone has rattled seller confidence.

Is Amazon Using a Secret Seller Reliability Index to Control Buy Box?

Since late June 2026, numerous established FBA sellers have reported sudden and unexplained drops in their Buy Box win rates. Many attribute this to an alleged internal metric called the “Seller Reliability Index” (SRI), which is reportedly being piloted by Amazon. According to ecommerce-times.com, the SRI is said to incorporate factors such as “suspicious” return reason codes and buyer sentiment analysis, beyond the publicly available account health scores.

The lack of transparency is the primary source of frustration. Sellers see their Buy Box access decline without any notification or explanation. The supposed index operates outside of the known performance metrics that sellers are accustomed to monitoring. This has led to widespread anxiety, especially as the Q4 shopping period approaches. Without clear guidance, sellers are left guessing how to improve their score.

Why Did Amazon Rewrite the Buy Box Algorithm in July 2026?

In late July 2026, Amazon implemented a significant, undocumented change to its Buy Box algorithm. The algorithm now heavily prioritizes delivery speed certainty, return rate history, and inventory depth, while deprioritizing sellers who rely on rule-based repricing tools. As reported by ecommerce-times.com, sellers are experiencing double-digit drops in Buy Box ownership even when they offer the lowest price.

This shift undermines a long-standing strategy: use aggressive repricing to win the Buy Box. Now, sellers with fast, reliable fulfillment and deep inventory — often those using FBA or SFP — have an advantage even at higher prices. The change is particularly disruptive for Q4 planning, as sellers have already set pricing strategies based on older algorithm behavior. Some are now scrambling to adjust their fulfillment methods and inventory management to align with the new priorities.

Broader Regulatory and Trust Challenges for Amazon Sellers

Beyond internal policy shifts, Amazon sellers face increasing external scrutiny. The U.S. Consumer Product Safety Commission (CPSC) issued a ruling in 2024 finding Amazon responsible for hazardous products sold by third-party sellers on its platform (CPSC). This decision has implications for seller liability and may lead to stricter product compliance requirements.

In California, authorities have alleged that Amazon colluded with sellers to raise prices, as revealed through internal emails (The Guardian). Such legal actions could reshape how Amazon manages pricing parity agreements.

Additionally, a Bloomberg investigation uncovered a shadow market where brokers sell access to Amazon employees for account reinstatements and preferential treatment — a bribery market that further erodes trust in the platform’s fairness.

Even AI-generated reviews are causing problems. Amazon sellers have reported that misleading AI product reviews threaten sales, especially during the holiday season (Bloomberg). And for sellers reliant on Amazon’s payment systems, there is the ongoing risk of funds being withheld, as documented by the BBC in 2023 (BBC). These issues compound the operational challenges of 2026.

What Should Amazon Sellers Do to Prepare for Q4 2026?

With so many changes converging, sellers must take proactive steps. First, audit your SFP same-day ship rates daily to avoid falling below the 93.5% threshold. Consider whether SFP is still viable or if shifting to FBA makes more sense given the fee structure. Second, recalculate margins under the new FBA fee tiers. The low-inventory surcharge means that maintaining consistent stock levels is now critical — consider using inventory planning tools to avoid stockouts and overstock penalties.

Third, diversify your fulfillment and sales channels. Relying solely on Amazon for traffic is riskier than ever. Platforms like Walmart Marketplace, eBay, and direct-to-consumer websites can provide a safety net. Fourth, stay informed about legal developments. The CPSC ruling and California price-fixing case could lead to new compliance requirements. Finally, join seller advocacy groups to share intelligence on undocumented changes — sellers are often the first to detect algorithm shifts.

The months ahead will test sellers’ agility. Those who adapt quickly and diversify their strategies will be best positioned to weather the storm and capture Q4 sales.