Overview

Error 100873 is a common listing error that Amazon sellers encounter when attempting to add a product using a barcode (EAN, UPC, or GTIN) that is already linked to a different ASIN in Amazon's catalog. Since Amazon enforces a strict one-to-one relationship between product identifiers and ASINs, this error blocks the listing process until the conflict is resolved. Understanding how to diagnose and fix this issue can save sellers significant time and prevent delays in getting products live.

Key Points / What Sellers Need to Know

• One barcode, one ASIN — Amazon's catalog requires that each product identifier (GTIN, UPC, or EAN) maps to only one ASIN at any given time, so duplicate assignments are automatically rejected.
• Existing catalog conflicts — The error triggers when the barcode you're submitting is already associated with a different product listing in Amazon's system, regardless of whether you own that listing.
• Resolution requires verification — Sellers must first check whether the existing ASIN matches their product before deciding on the correct resolution path.
• Support case may be needed — If the barcode is incorrectly mapped to the wrong ASIN, sellers need to open a case with Amazon Seller Support and provide documentation to prove ownership of the product identifier.

Why This Error Occurs

Amazon maintains a global product catalog where each barcode serves as a unique identifier tied to a single ASIN. When a seller tries to create a new listing or update an existing one using a barcode that Amazon has already mapped to a different ASIN, the system returns Error 100873. This can happen for several reasons: another seller may have already listed the same product under a different ASIN, the barcode may have been incorrectly assigned to an unrelated product, or there could be a data entry mistake in the barcode itself. In some cases, counterfeit or misused barcodes purchased from unauthorized resellers can also trigger this conflict.

How to Resolve the Error

The first step is to search for the barcode in Amazon's catalog to identify which ASIN it is currently assigned to. If the existing ASIN matches the product you are trying to list, you do not need to create a new listing — simply add the existing ASIN to your catalog and list your offer against it. This is the fastest resolution and requires no intervention from Amazon support.