What a GTIN Is and Why Google Wants It
A Global Trade Item Number, or GTIN, is the number under a product's barcode. Manufacturers license these numbers through GS1, the standards body that runs the barcode system, and assign one to each product and variant they make. Google accepts several formats:
- UPC (GTIN-12): 12 digits, used in North America. Convert 8-digit UPC-E codes to the full 12 digits.
- EAN (GTIN-13): 13 digits, used in Europe and many other markets.
- JAN: 8 or 13 digits, used in Japan.
- ISBN: 13 digits for books. Convert ISBN-10 numbers to ISBN-13.
- ITF-14 (GTIN-14): 14 digits, used for multipacks.
Google uses the GTIN to match your offer to its product catalog, to the searches shoppers run, and to product reviews. Google warns that products with missing or incorrect GTINs may get limited visibility, and that it could disapprove a product submitted without the GTIN its manufacturer assigned.
The GTIN Errors You Will See
Merchant Center lists GTIN problems under Products, in the Needs attention tab. Each error points to a different cause:
- Invalid value or unsupported format: The number has the wrong length, contains letters or symbols, or fails the check digit test.
- Incorrect GTIN: The number is valid but belongs to a different product.
- GTIN not associated with the brand: The number does not match the brand you submitted.
- Restricted GTIN: The number starts with 2, 02, or 04, ranges stores use for in-house codes.
- Unsupported GTIN: The number is a coupon code starting with 05, 981 to 984, or 99.
- Missing GTIN: Google expected a GTIN for the product and found an empty field.
Invalid Format: Length, Characters, and Check Digits
Google accepts GTINs of 8, 12, 13, or 14 digits. It ignores spaces and dashes but rejects any other character, so a value like "UPC-0123ABC" fails. The last digit of every GTIN is a check digit, calculated from the digits before it. GS1 multiplies those digits by alternating weights of 3 and 1 from the right, adds the results, and picks the digit that brings the total up to the next multiple of ten. One mistyped digit breaks that math, and Google rejects the code.
Spreadsheets introduce errors you will not spot by eye. Excel and Google Sheets treat a GTIN as a number, so they strip leading zeros. A valid UPC of 012345678905 turns into 12345678905, which has eleven digits and fails. Excel also displays long values in scientific notation, and a 13-digit EAN saved to CSV in that state can come out as 1.23457E+12 with its final digits gone. Format the GTIN column as text before you paste or import anything, and spot-check rows after each export.
Restricted and Coupon Prefixes
Google rejects GTINs that start with 2, 02, or 04 and flags them as restricted. GS1 sets those ranges aside for restricted circulation: codes a store assigns for its own use to weighed deli items, in-house stock numbers, and products that never leave the shop. Coupon codes trigger a separate error. GTINs starting with 05, 981, 982, 983, 984, or 99 identify coupons, and Google marks them as unsupported.
Restricted codes tend to enter feeds in two ways. A supplier may hand you its internal stock codes and label them as barcodes, or someone on your team may have filled the field with placeholder numbers to clear a missing-GTIN warning. Replace these with the manufacturer's GTIN, or leave the field empty if the product has none.
Incorrect GTIN and Brand Mismatches
An incorrect GTIN passes the format check but belongs to a different product. Google says this tends to happen when someone reuses the GTIN from another product. You see it most when your team duplicates a listing to create a new variant and forgets to change the barcode.
A brand mismatch means the GTIN does not belong to the brand you entered. Look for three causes:
- You entered your store name as the brand for a product another company manufactures.
- Your supplier gave you GTINs registered to a different company.
- You bought barcodes from a cheap reseller, and the numbers belong to another business's GS1 registration.
Check suspect codes with GS1's Verified by GS1 lookup, which shows the company that licensed each number. Give each product and each variant its own GTIN. Google does not allow the same GTIN on multiple products in the same country and language when they share the same variant attributes: condition and multipack for all products, plus color and size for apparel.
Missing GTINs and the identifier_exists Attribute
Plenty of products have no GTIN. Store brands, private-label goods, and custom products often have none, and Google tells you to leave the field blank in that case. Its guidance reads: "When in doubt don't provide a GTIN." For private-label products, submit brand and MPN in its place.
For custom, handmade, and one-of-a-kind items, and for vintage goods or books published before 1970, set identifier_exists to no. Use it only when you are certain the product has no identifier. If Google finds evidence that a GTIN exists, the product receives a warning.
Dozens of Products Flagged and No Clear Cause?
GTIN warnings sometimes sit on top of a bigger problem in the feed or the account. Send us your Merchant Center account details and a sample of the flagged products, and within 48 hours you get a written read on what is behind them and whether the case has a clear path back.
Bundles, Multipacks, and Special Cases
- Manufacturer bundles and multipacks: Submit the GTIN, MPN, and brand of the bundle or multipack itself.
- Bundles you create: Submit the GTIN, MPN, and brand of the main product and set the bundle attribute.
- Multipacks you create: Submit the individual product's GTIN, MPN, and brand along with the multipack quantity.
- Customized products: Submit the manufacturer's GTIN and describe the customization in the title and description.
- Used and refurbished goods: Submit the manufacturer-assigned GTIN and set the condition attribute to match.
- Books: Use the ISBN-13. If a book carries both a UPC and an ISBN-13, submit both values.
How to Fix GTIN Errors Across Your Feed
- Open Products, select Needs attention, and filter by the GTIN issue.
- Download the affected products as a CSV.
- Pull the manufacturer GTIN for each item from the packaging or supplier data, and confirm it with the GS1 check digit calculator.
- Correct the values at the source: your store platform, your feed file, or a supplemental data source. If you keep GTINs in a supplemental source, confirm that it syncs with your primary feed.
- Re-upload the data or wait for the next scheduled fetch.
Google takes 24 to 72 hours to update the Needs attention page. If a GTIN change affects product ratings, allow another 7 to 10 days for review data to sync.
When GTIN Errors Turn Into Account Problems
Google treats GTIN errors as product-level issues. They disapprove or limit individual items, and a mistyped check digit will not get your Merchant Center account suspended or put a Google ads account suspended notice in your inbox. The risk grows when GTIN data becomes part of a wider pattern of misleading product information: barcodes lifted from a well-known brand, brand fields that claim a manufacturer you do not represent, or product pages that contradict the feed.
Google reviews patterns like these under its misrepresentation policy, which can suspend the entire account. Our guide on how to Resolve Google Merchant Center Misrepresentation Policy covers the account-level fixes.
Shortcuts That Make GTIN Errors Worse
Some fixes clear the warning today and cost you more later:
- Inventing numbers that pass the check digit test. Google can match an invented code to another company's product and flag it as incorrect.
- Copying a competitor's GTIN for a similar product.
- Setting identifier_exists to no on branded products to hide the missing-GTIN warning.
- Opening a new Merchant Center or Google Ads account to relist products Google disapproved.
The last shortcut carries the most risk. On the Google Ads side, creating accounts to get around enforcement falls under the Circumventing Systems policy, which Google treats as egregious. If Google has already applied it to you, our guide on how to Resolve Google Ads Circumventing Systems Policy explains the appeal path.
The Bottom Line
Each GTIN error points to a specific defect: the wrong length, a failed check digit, a restricted or coupon prefix, a code borrowed from another product, or a brand that does not match. Format the column as text, pull codes from the manufacturer, leave the field blank for products without one, and fix errors in bulk from the Needs attention tab.
If GTIN errors keep returning after you fix them, or your account has moved from product warnings to an account-level issue, Get a Free Preliminary Assessment and our team will trace the cause in your feed.
