Every detection signal, from image matching to price tracking, answers the same underlying question: should this seller be selling this product? Without an authorized seller list, that question has no definitive answer, so every flag becomes a judgment call that a reviewer has to research from scratch. With a list, detection becomes arithmetic. A seller is either on the list or it is not, and the not-on-the-list sellers get flagged automatically. Most brands skip this step and then wonder why their detection produces noise instead of cases.
Every entity authorized to sell your products on each marketplace, named the way the marketplace names them: the exact storefront name, the seller ID, and the marketplace. Include your own direct storefronts, your distributors and their sub-distributors, authorized resellers, and any liquidation or outlet partners. Record the date each authorization started and ended, because a seller that was legitimate in 2024 and lost authorization in 2025 is exactly the kind of account counterfeit networks love to acquire. The list is a living document, not a one-time spreadsheet; stale entries are worse than missing ones because they actively suppress legitimate flags.
It converts the hardest detection problems into the easiest ones. A new seller appearing with your product photos used to require image analysis and a review. Against an authorized list, it is a single lookup: not on the list, flag it. The list also sharpens every other signal. Price tracking is far more useful when you can distinguish an authorized reseller clearing old stock at a discount from an unauthorized seller undercutting at the same price. Seller name churn detection gets simpler too, because you can track which unauthorized names keep reappearing instead of re-investigating each one.
Three places. First, distributors: brands know their direct resellers but have no idea who their distributors sell to, and those sub-distributors are where unauthorized listings breed. Require distributors to report their downstream sellers as a contract term. Second, old authorizations: nobody revokes the reseller agreement from 2022, so the list accumulates dead entries that whitelist sellers who should be flagged. Audit the list quarterly. Third, marketplace name mismatch: the legal entity name on your contract is not what appears on the storefront, so the list has to capture storefront display names and seller IDs, not just company names.
Assign an owner, which is usually someone in sales or partnerships who actually signs reseller agreements. Feed every new authorization and every terminated agreement into the list the same week it happens. Reconcile quarterly against what your detection system sees: authorized names that never appear are dead entries to remove, and appearing names that are not on the list are either new authorizations to add or flags to file. The reconciliation loop is the whole point. A list that never gets checked against reality rots, and a rotten list teaches your detection to ignore the exact sellers it should be catching.
A detection queue that is mostly high-confidence unauthorized sellers instead of a mix of maybes. Review time per flag drops because the reviewer is confirming a list mismatch, not investigating from zero. And the brand starts catching sellers in their first week instead of their first quarter, because the list flags them on day one rather than waiting for a signal pattern to accumulate. The authorized seller list is the least glamorous part of counterfeit detection, which is exactly why skipping it costs more than any single feature you could buy instead.