FeedMender/Errors/Invalid GTIN
Common rejections
Invalid value [gtin]
A rejected barcode is rarely a typo. Far more often it is a correct barcode that was damaged in transit, by a spreadsheet, an export, or a truncation, and damage follows patterns a machine can recognise and sometimes reverse.
What Google requires
Right length, right check digit
A GTIN is 8, 12, 13 or 14 digits, and its last digit is a GS1 mod-10 check digit computed from the others. Google verifies both, so a barcode that fails the arithmetic is refused no matter how plausible it looks. ISBN-10 and UPC-E are real identifier formats but not valid GTIN submissions: the ISBN-10 must be converted to its ISBN-13 form and the eight-digit UPC-E expanded to UPC-A before Google will take them.
What happens if you do not
The product is disapproved, and the cause hides upstream
The classic case is Excel: opened once, saved once, and every long barcode becomes scientific notation such as 8.71234E+12 while every leading zero disappears. The database was right, the shelf label is right, and the feed is wrong. Truncated exports produce eleven-digit UPCs the same way. Each of these fails the length or the check digit and blocks the product entirely, unlike the missing-GTIN warning, this one is a refusal.
How to fix it by hand
Repair the transport, not the barcode
- Store and export barcodes as text. In Google Sheets, import with automatic conversion switched off; in Excel, format the column as text before pasting.
- Restore lost leading zeros by padding UPC-A to 12 digits and EAN to 13.
- Convert ISBN-10 to ISBN-13 (the prefix 978 and a recomputed check digit) and expand UPC-E.
- Where the check digit fails after all that, get the barcode again from the source rather than guessing a digit: a barcode that passes the arithmetic but belongs to another product is a worse outcome than a rejection.
Which of our checks apply
5 checks apply, read from the scanner's registry
The scan distinguishes a wrong barcode from a damaged one: scientific notation, stripped zeros and stray separators are recognised as repairable and repaired, with the check digit re-verified afterwards. We never invent a digit.
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The quicker way
Let the scan find them
Run the free scan and it will tell you, per product, whether the barcode is wrong or merely damaged, and repair the damaged ones. The scan to identify errors is free and shows every finding before you pay anything. You only pay for the fix.