Missing value [mpn]

What this error means

The mpn, or manufacturer part number, is one of the identifiers Google uses to recognise a product. It is expected here and is missing, which limits or disapproves the item.

Why it happens

MPN mainly matters for products that do not have a GTIN, though some products carry both. For products without a GTIN, Google often expects the brand and mpn together to identify the item, and the exact requirement can vary by product type. The value is usually missing because the store holds the manufacturer number in a field that is not mapped to the feed, or because the product record never had one entered. Products that have a valid GTIN often do not require an MPN.

How to fix it

1. Decide whether the product has a GTIN. If it does, supply that and the MPN requirement typically falls away.
2. For products without a GTIN, add the manufacturer part number and supply both brand and mpn.
3. Use the exact part number the manufacturer assigns, not an internal store code.
4. For genuinely identifier-free products such as custom or handmade goods, set identifier_exists to no, and only when the product truly has no GTIN, MPN, or brand to provide.
5. Update the feed and wait for re-crawl.

Fixing it in your store

The manufacturer part number usually lives in a product field or a custom attribute in your store. This error means that field is not reaching the feed. Map whichever field holds the real MPN to the mpn attribute, fill the gaps for products that need it, and use the identifier_exists signal only for products that truly have no identifiers.

How long until it clears

After the MPN is in the feed and re-crawled, expect the product to qualify within 1 to 3 days.