Facebook catalog missing GTIN or MPN: Shopify guide

Do not invent a barcode. Use the real UPC/EAN/GTIN when the manufacturer assigned one; otherwise use truthful brand and manufacturer part information where supported.

Common causes

• The barcode field was never populated.
• A private-label product has no universal barcode.
• Variant-level identifiers are missing.

What to check first

1. Ask the manufacturer for the real barcode.
2. Check each variant because sizes or colors can have different GTINs.
3. Confirm vendor/brand and part references are truthful.

How to resolve it

1. Enter the valid barcode on each Shopify variant.
2. For products without GTIN, provide brand plus a stable manufacturer part number where the channel supports it.
3. Never buy or generate fake identifiers merely to clear a warning.