Product missing unique identifier (GTIN, MPN, brand)

Each product Pin must represent a specific item, which Pinterest verifies through unique identifiers like GTIN, MPN, or brand.

Pinterest Catalogs uses identifiers (GTIN, MPN, brand, SKU) to match catalog records. Issues come from invalid format (non-numeric in a GTIN field), brand-GTIN mismatches in GS1's database, duplicate IDs across SKUs, or missing required identifiers for the category.

1. Verify GTIN ownership using GS1 GEPIR (https://gepir.gs1.org) — confirms which brand legitimately owns the code.
2. Strip non-numeric characters from GTINs: no dashes, no letters, no spaces.
3. Check ID lengths: UPC = 12 digits, EAN-13 = 13 digits, ISBN-13 = 13 digits starting 978/979.
4. If your product is private-label without a real GTIN, request the channel's GTIN exemption process rather than fabricating one.
5. Re-submit; new identifiers take 24–72 hours to propagate.

• Buying GTINs from non-GS1 resellers — usually maps to defunct brands and triggers validation
• Reusing the same GTIN across multipack and single-unit variants — flagged as duplicate