What are unique product identifiers (UPIs). Google said a unique product identifier, also known as UPIs, are considered products that include Global Trade Item Numbers (GTINs), Manufacturer Part Numbers (MPNs), and brand names in the product feed you submit to Google Merchant Center.

Previous enforcement. In September, Google said if a product listing was missing these required attributes, the product was immediately disapproved and no longer shown in free listings. Google said “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.” Google said then, “beginning September 15, 2021, the following enforcement will apply to products shown in free listings.”

New rules. Now, starting in November 2021, “with the introduction of limited performance enforcements, products that are missing such attributes will remain eligible to serve but their performance may be limited,” the company said.

Why we care. If you are taking advantage of the free Google Merchant Center and you are not using UPIs on your products in those feeds, you previously may have seen those products being rejected and disapproved. Now, instead, those product listings will likely continue to be served but their performance in Google Search may be limited.