MPN
MPN is the manufacturer's part number for a product or spare part, used with the brand in product feeds when a GTIN is missing.
What is MPN?
MPN stands for Manufacturer Part Number and is the identifier a manufacturer assigns to a specific product or spare part. Unlike a SKU, which you invent yourself for your own inventory, the MPN comes from the manufacturer and stays the same no matter which retailer sells the item. An MPN is only unique within a single manufacturer, so it should always be paired with the brand to identify a product unambiguously.
Why does MPN matter?
Price comparison sites and Google Shopping use the MPN to match identical products across different retailers. If a product has no GTIN (barcode/EAN), the brand + MPN combination can serve as a valid product ID in your product feed. A correct MPN means better matching, fewer feed rejections, and eligibility to appear in comparisons. If an item has neither a GTIN nor an MPN — for example handmade products — you should instead flag that no identifier exists.
Common use cases
- Google Merchant Center feeds, where
mpnis filled in alongsidebrandfor products without a GTIN. - Spare parts and B2B goods, where customers search directly by the manufacturer’s part number.
- Structured data with
Productschema, where thempnproperty helps search engines identify the item. - Matching against the manufacturer’s catalog during price updates and inventory imports.
Shopify perspective
Shopify has no dedicated MPN field — a variant only holds the SKU and Barcode (ISBN, UPC, GTIN...) fields. The MPN is therefore usually stored in a metafield (e.g. custom.mpn) and mapped from there into your product feed via a feed app like Google & YouTube or a comparable integration. Keep the naming consistent so automated feeds and integrations can read the field without manual cleanup.