Multi-channel products unified; separate IDs required when online and in-store attributes differ (March 2026)

From March 2026 Merchant Center manages products sold both online and in store as a single product, with online attributes as the default. Merchants needing different price, availability or condition per channel must submit two products with distinct IDs. Content API local-channel updates for multi-channel products are rejected.

Google's help article warns that submitting the same product ID, language and feed label through multiple sources, or mixing multi-channel and local-only products with identical IDs, now triggers errors. New Merchant API data sources default to multi-channel, and BigQuery exports multi-channel products with the online channel.