Download the affected-products CSV
In Merchant Center, open Products → Needs attention, filter for the missing GTIN issue, and download the affected-product list. Keep Google’s product ID values unchanged.
Missing value [gtin]
Trace missing GTIN warnings to the source rows.
Cross-reference Google’s affected-products CSV with the feed that generated it, then verify the real identifiers at their source before changing product data.
Open the feed that supplied those offers
Choose the CSV or TSV that generated the affected products. FeedPatch audits the file locally and records original source-row numbers; it does not upload your catalog.
Match every affected ID to a source row
Add Google’s affected-products CSV to the ID-list slot. The free matcher produces matched and unmatched IDs so you can investigate the exact rows instead of searching the catalog one item at a time.
Confirm whether a GTIN really exists
Check manufacturer packaging or an authoritative manufacturer record for the exact product and variant. Google says submitted GTINs must be allocated by the manufacturer. A store SKU, another variant’s barcode, or an invented number is not a substitute.
Handle products without identifiers honestly
If a product genuinely has no assigned unique product identifier, follow Google’s identifier rules for that product. Do not use identifier_exists=no merely to suppress a warning for a product that actually has a GTIN.
Correct the source of truth and re-upload
Update the original data source, review the affected-row map, and upload the corrected product data once. Then monitor Needs attention; Merchant Center may not reflect the change immediately.
Product boundary
Locate the row here. Confirm the identifier at its real source.
FeedPatch can flag a missing identifier combination and match Google IDs to source rows. It cannot query GS1, inspect packaging, see every Merchant Center data source, or decide whether a product should have a GTIN.
Run the free feed auditOptional repair export
Locate identifier gaps free. Upgrade for the corrected full-feed download.
FeedPatch Pro applies safe, reviewable formatting normalizations after you identify the correct source rows. It never invents or substitutes product identifiers.
$79USD
per year
per year
- Free identifier and affected-row checks
- Full-feed safe normalization export
- Source feeds up to 100 MB
- 14-day refund policy
Frequently asked
Before adding a barcode.
Why does Merchant Center report missing value [gtin]?
Google suspects the product normally has a manufacturer-assigned GTIN, but the submitted product data did not include one. Products with an assigned GTIN but no submitted value can have limited visibility.
Can FeedPatch tell me the correct GTIN?
No. FeedPatch can locate affected source rows and flag file-level identifier gaps. Manufacturer records, packaging, and Merchant Center remain the authority for the product’s identity.
What does the free matcher return?
When the affected-products export and source feed share product IDs, it returns exact source-row numbers, matched and unmatched counts, and a downloadable match map.
Should I copy a barcode from another variant?
No. Each variant that has its own GTIN needs the identifier assigned to that exact variant. Reusing or inventing a GTIN can create a different identifier problem.
Official references
Use Merchant Center and manufacturer data as the final authority.
Google: Fix missing value [gtin]Affected-products download, cross-reference, correction, and re-upload workflow.Google: GTIN [gtin] specificationManufacturer allocation, supported formats, variants, and identifier requirements.Google: identifier_existsWhen a product genuinely lacks unique product identifiers.
Published by the FeedPatch team, the developer of the tool described here. Checked against Google Merchant Center Help on September 4, 2026. FeedPatch is independent and is not affiliated with Google.