Invalid GTIN in Google Merchant Center: causes and fixes
Google rejects a GTIN if it has the wrong length, a wrong check digit, a restricted prefix (in-store or coupon numbers) or does not belong to the product. Copy GTINs from the packaging or the manufacturer – and for products without one, leave gtin empty and submit brand + mpn or identifier_exists = no instead of inventing a number.
Check every GTIN of your feed – length, check digit and restricted prefixes – plus all other attributes Google requires.
Open the feed validatorWhat a valid GTIN looks like
GTIN is the umbrella term for the barcode numbers on products. Google accepts these lengths:
- GTIN-8 (EAN-8)
- GTIN-12 (UPC-A, mostly North America)
- GTIN-13 (EAN-13, most of the world)
- GTIN-14 (ITF-14, multipacks)
The four most common causes
- Wrong length or characters: letters, too many or too few digits (often an internal SKU in the gtin column).
- Wrong check digit: a typo or a number that was changed by a spreadsheet (leading zeros removed, scientific notation such as 4.00638E+12).
- Restricted prefixes: numbers for in-store use (prefixes 02, 04 and 2 on the 13-digit form) and coupon numbers (98–99) are not product GTINs.
- Real number, wrong product: a valid GTIN that belongs to another product or brand – for example reused from a similar item.
How the check digit is calculated
The last digit of every GTIN is calculated from the others. Starting from the right (without the check digit), the digits are multiplied alternately by 3 and 1 and added up; the check digit is the amount needed to reach the next multiple of 10.
If your product has no GTIN
Own brands, handmade items, custom products and some spare parts have no GTIN. Do not invent one: leave the gtin attribute empty, submit brand and mpn (manufacturer part number) if you have them, or set identifier_exists to no.
Worked examples: Checking 4006381333931
A GTIN-13 from a product feed, and the same number with a typo in the last digit (4006381333932).
- Digits without check digit
- 400638133393
- Weighted sum (3,1,3,1 … from the right)
- 89
- Next multiple of 10 minus sum
- 1
- Result for 4006381333931
- valid
- Result for 4006381333932
- wrong check digit
One wrong digit is enough for Google to reject the GTIN. The feed validator recalculates the check digit for every product in your file.