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Merchant Center issue

Fix invalid GTIN in unsupported format

Merchant Center raises "Invalid GTIN in unsupported format" when the value in your gtin field is not a GTIN it can accept. Most of the time it is a typo, a stray letter or a number with the wrong length. This page covers the format rules, the two related GTIN warnings Google shows for reserved and bulk ranges, and how to fix them in bulk.

Diego Nijboer · WISEPIMLast updated:

Short answer

Send the manufacturer's GTIN as digits only, with 8, 12, 13 or 14 digits and a correct check digit. Remove spaces, dashes and letters, and never make up a number. Correct one product with Edit product under Needs attention, or download the affected products, fix your data and upload it again. Updates can take 24 to 72 hours to show.

What this issue means

A GTIN is a numeric barcode number assigned by the manufacturer through GS1. Google checks every submitted value: it has to contain digits only, have 8, 12, 13 or 14 digits, pass the GS1 check digit calculation and follow a standard GTIN type. When a value fails one of those checks, Merchant Center rejects it and shows this issue. The gtin attribute allows at most 14 digits and asks you not to guess.

Two related warnings are about valid looking numbers in the wrong range. Restricted GTIN means the number sits in a range reserved for future use, with prefixes 2, 02 or 04, and must not be submitted. Unsupported GTIN means the number is meant for bulk sales (the indicator digit 9 range); use the manufacturer's GTIN of the single item you sell instead.

DetailValue
Issue in Merchant CenterInvalid GTIN in unsupported format
Attributegtin [gtin]
EffectMerchant Center rejects the GTIN value, so the product needs a valid GTIN before it can show with full performance.
CheckedAgainst Google Merchant Center Help on 11 October 2026

Common causes

  • The value contains letters, spaces, dashes or other non-numeric characters.
  • The number has the wrong length; valid GTINs have 8, 12, 13 or 14 digits.
  • The check digit does not match, usually because of a typo or a digit lost when a spreadsheet stored the code as a number.
  • The value is not a standard GTIN type, for example an internal SKU or a supplier article number in the gtin field.
  • The number is in a restricted range (prefix 2, 02 or 04) or is a bulk GTIN instead of the GTIN of the single item.

How to fix it, step by step

  1. In Merchant Center, open Products, go to the Needs attention tab and filter on this issue.
  2. For a few products: click the product, choose Edit product, enter the correct GTIN and save.
  3. For many products: download the affected products as a CSV file and match them against your own product data.
  4. Strip everything that is not a digit and check the length is 8, 12, 13 or 14.
  5. Test each check digit, for example with the EAN/GTIN validator in batch mode or GS1's check digit calculator. A failed check usually means a typo, so compare with the barcode on the packaging.
  6. Replace restricted (prefix 2, 02 or 04) and bulk GTINs with the manufacturer's GTIN of the single saleable item. If the category does not require a GTIN and none exists, leave the field empty.
  7. If GTINs reach Merchant Center through a supplemental data source, make sure it is set up and synced with your primary source so it does not overwrite your fix.
  8. Upload the corrected data the way you normally do and check Needs attention again after 24 to 72 hours.

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Check a product against Google Shopping rules

Enter one product's title, description, price, GTIN and image link. The checker lists the errors and warnings Merchant Center's core requirements would raise, before you upload.

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How to prevent it

  • Store GTINs as text, never as numbers, so leading zeros and long codes survive spreadsheets and exports.
  • Only accept GTINs assigned by the manufacturer; never generate or guess one.
  • Validate length and check digit when supplier data comes in, not after Google rejects it.
  • Keep the GTIN of the single item separate from case or pallet codes in your supplier data.

How WISEPIM helps

The Google Shopping rule pack in Quality Guard blocks a product whose GTIN (EAN field) has an invalid GS1 check digit, and warns when the EAN is missing, so a typo is caught inside WISEPIM. The general packs also flag a GTIN that is used twice in the same project.

The Merchant Center connection only sends a GTIN when its check digit is valid. To check a supplier list before import, paste it into the free EAN/GTIN validator: it checks digits, length, check digit and the GS1 prefix country. It does not look numbers up in the GS1 registry, so it cannot tell you whether a valid number belongs to the right product.

Sources

Vendor documentation we read for this guide, as of October 2026. Features and names change, so check the current documentation before you decide.

Frequently asked questions

You do not need to. Google accepts GTINs of 8, 12, 13 or 14 digits, so send the number as the manufacturer printed it. The problem is usually the opposite: a spreadsheet that dropped a leading zero.

GTINs with the prefixes 2, 02 and 04 are in a range reserved for future use, and Google shows them as Restricted GTIN. Do not submit them. If your product category does not require a GTIN, you may leave the field empty.

Changes can take 24 to 72 hours to show on the Needs attention tab. If the new GTIN also affects how Product Ratings are matched, Google says to allow 7 to 10 days.

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