How Can You Monitor Unauthorized Resellers on Amazon?

Unauthorized resellers pose a serious risk to brands — they can disrupt pricing strategies, damage reputation, and degrade the customer experience. Yet retailers, manufacturers, and brands often feel powerless to stop them.

The threat is especially high for large brands and manufacturers, particularly those selling premium or high-margin products. Unauthorized resellers frequently violate minimum advertised price (MAP) agreements, undercutting legitimate sellers. Some even sell counterfeit products, further harming brand trust.

This issue is especially challenging for ecommerce brands on Amazon, where an open marketplace structure and algorithm-driven pricing make it easy for unauthorized resellers to infiltrate listings.

Here’s what you need to know about identifying and managing unauthorized resellers on Amazon — plus tools to monitor prices and protect your brand.

Why unauthorized resellers are such a problem on Amazon

Amazon is a dominant force in global ecommerce, so it’s surprising that unauthorized resellers remain such a widespread issue. (Or rather, why sellers have to deal with unauthorized resellers — Amazon itself isn’t particularly affected.) 

There are a few key reasons for the prevalence of these resellers, starting with how Amazon structures its marketplace.  

Amazon’s open marketplace structure enables third-party resellers

Amazon’s marketplace model is semi-open — almost anyone willing to pay the fee can create a seller account and list products. Since most products aren’t exclusive to a single vendor in Amazon’s eyes, multiple sellers can offer the same item.

With such a low barrier to entry and few restrictions on who can sell what, Amazon inherently encourages third-party resellers. Because the platform doesn’t strictly enforce authorization, it’s easy for unauthorized sellers to compete alongside legitimate brands.

The lack of strict seller vetting makes unauthorized selling easier

Amazon does little in the way of seller vetting. Aside from a handful of restricted categories that require additional screening and approval, resellers can list and sell nearly any product allowed on the platform. 

While third-party resellers generally can’t sell Rolexes or fine art, categories like office supplies, personal electronics, and accessories are fair game.

Buy Box competition incentivizes aggressive price undercutting

Amazon prioritizes sales, awarding the coveted Buy Box to the seller its algorithm decides is most likely to convert. Remember, from Amazon’s perspective, it doesn’t matter who makes the sale — it still takes its cut. It just matters that a buyer actually purchases the product. 

Since the A10 algorithm often (but not always) favors the lowest price it finds, reseller price competition plays a major role in winning the Buy Box. Third-party and unauthorized resellers frequently undercut a brand’s standard price to gain an advantage, diverting sales from authorized first-party sellers.

Signs you have unauthorized Amazon sellers selling your products

If you’re reading this, you likely suspect an issue with unauthorized sellers — but it’s important to be certain. Here are three red flags that indicate you’ve got a problem:

• Sudden price drops: If your product’s price drops unexpectedly — especially when using a repricing tool — it could signal increased (and possibly illegitimate) competition. 
• Loss of Buy Box control: If you’ve consistently won the Buy Box but suddenly lose it without a clear cause, unauthorized sellers may be undercutting your pricing.
• Customer complaints about product quality or consistency: Unauthorized resellers may sell defective, imitation, or knock-off versions of popular products. Since consumers assume they’re purchasing from you, their negative user experiences can damage your brand’s reputation. If you notice an uncharacteristic uptick in complaints about faulty or subpar products, it may indicate unauthorized resellers are cutting corners and misleading customers.

Other indicators include fake ASINs, ASIN piggybacking, and odd seller names that don’t align with your brand. To stay ahead, brands should regularly monitor listings for unusual seller activity, pricing data fluctuations, and product availability changes. Early detection is key to stopping unauthorized resellers before they impact your brand.

How to practice reseller monitoring with Jungle Scout’s tools

To protect revenue and brand integrity, sellers must stay vigilant in monitoring for unauthorized resellers. Jungle Scout offers powerful tools to help brands track and address reseller activity efficiently.

Using pricing insights to detect MAP violations

Manufacturers and intellectual property holders set minimum advertised price (MAP) agreements to maintain pricing integrity. While MAP policies aren’t legally enforceable, they establish clear expectations for resellers. Those who violate MAP by advertising prices below the agreed threshold risk losing access to a manufacturer’s products, discounts, or purchase agreements.

However, enforcing MAP is entirely up to the brand. Manufacturers or IP holders must first identify violations and decide how to respond. Research from Harvard Business Review found that while authorized resellers violate MAP around 20% of the time, unauthorized resellers do so at a rate of about 50% — meaning brands that don’t monitor pricing are likely being undercut.

Jungle Scout’s Cobalt Retail Insights equips enterprise brands with powerful price tracking capabilities, monitoring fluctuations and seller performance through the Segments tool. This allows brands to detect MAP violations more efficiently and take action in real time. 

While Cobalt doesn’t track price fluctuations as they happen, brands can leverage historical trends and competitor price data to pinpoint repeat offenders and pricing inconsistencies. Some brands create segments by price band to compare revenue impact across different pricing tiers, making it easier to spot patterns and enforce MAP policies more effectively. 

Additionally, Cobalt allows brands to compare their pricing strategies with competitors’ using key metrics, helping them optimize pricing without undermining their own value.

Monitoring Buy Box data

Controlling the Buy Box is critical — no matter how much effort you put into Amazon search engine optimization (SEO), it won’t matter if an unauthorized reseller takes over the Buy Box.

Jungle Scout Cobalt helps by allowing you to monitor Buy Box wins and ownership percentages for every ASIN you sell. If your ownership drops below 100%, you can investigate that particular ASIN to see if any unauthorized sellers have taken over the Buy Box, then take proactive steps to regain control, including:

• Enforcing MAP policies
• Adjusting broader pricing strategies
• Reporting unauthorized sellers through Amazon’s enforcement channels

Analyzing seller behavior over time

One-time reseller incidents may not be the biggest threat — it’s repeat offenders that cause the most damage. Cobalt’s long-term seller tracking (up to two years) helps brands identify behavioral patterns, such as sellers who routinely undercut pricing, win the Buy Box, or sell in unauthorized regions.

Instead of chasing one-off violators, your business can focus on the resellers doing the most harm, protecting distribution channels, eliminating counterfeit sales, and maintaining brand integrity.

Additionally, Cobalt’s Segments tool allows brands to track reseller activity across multiple ASINs, create seller-specific segments, and monitor revenue and sales trends over time.

Protect your brand with proactive reseller monitoring

Unauthorized resellers on Amazon can erode pricing, damage brand reputation, and weaken consumer trust. Many undercut prices to win the Buy Box, while others sell low-quality or imitation goods that harm your brand image. Without active reseller monitoring, brands risk losing control over their listings and revenue.

Jungle Scout Cobalt provides the reseller monitoring tools enterprise brands need to track unauthorized sellers, detect MAP violations, and maintain control over pricing and distribution. 

Our powerful Amazon seller management software delivers the functionality required to monitor resellers at scale. Automations improve scalability without increasing bandwidth demands, while in-depth insights help brands make data-driven decisions to protect their market position.