Providing the correct unique product identifiers (UPIs) for your products ensures that Google recognizes them and can provide optimal customer experience. Common UPIs include Global Trade Item Numbers (GTINs), Manufacturer Part Numbers (MPNs), and brand names.
In order to unify the enforcement of UPIs across programs, specifically the enforcement for multiple different products that use the same GTIN, we’re expanding this enforcement and applying it to products listed in free listings.
Beginning September 15, 2021, the following enforcement will apply to products shown in free listings: Different products that use the same GTIN with the same variant attributes will be considered ambiguous and will be disapproved. Variant attributes include condition[condition] and multipack [multipack] for all products, as well as color [color] and [size] for apparel products. If a group of products are identified as duplicates, only one will remain active and eligible to show in free listings.