GTIN not valid: check digits and the usual causes

What Google's message means

The gtin value fails Google's checksum or format check — a typo, a supplier code that is not a real barcode, a restricted range, or a GTIN with spaces or letters.

Disapproved: Google treats a wrong GTIN as misidentifying the product.

The fix in Shopify

1. Products → the product → each variant → Barcode (ISBN, UPC, GTIN, etc.): enter the full barcode digits — EAN-13 in India and Europe, UPC-12 in the US, ISBN-13 for books. Save.
2. Only digits, 8, 12, 13 or 14 of them, no spaces. A SKU, supplier code or model number does not go in Barcode — clear it there.
3. No barcode at all (handmade, custom, vintage): Products → select them → Bulk edit → Columns → add ‘Google: Custom product’ → set it to TRUE; the app then sends identifier_exists: no. Fill Vendor as the brand. Save.
4. Google re-checks the product at its next crawl (usually within a day); the next RevenueCue scan confirms it's clear.

The fix in WooCommerce

1. Products → the product → Product data → Inventory → ‘GTIN, UPC, EAN, or ISBN’ (WooCommerce 9.2+; on variable products, each variation's own field): enter the full barcode digits. Update.
2. Only digits, 8, 12, 13 or 14 of them, no spaces. A SKU or model number goes in SKU or MPN, never in the GTIN field — clear it there.
3. No barcode at all (handmade, custom, vintage): leave the GTIN field empty and fill Brand and MPN on the Google for WooCommerce tab, so Google gets brand + MPN instead.
4. Google re-checks the product at its next crawl (usually within a day); the next RevenueCue scan confirms it's clear.

What it costs while it's down

Every product Google flags this way is out of Google Shopping — no ads, no free listing — until it's fixed. Its listed price is what isn't being shown; a free scan names each product and adds up the listed value at stake.