Fix Code & Barcode Errors

You hit an error message; these guides walk you out of it step by step — what it actually means, what to check first, and what to send support if nothing works. Every fix is grounded in the official platform documentation.

Amazon listing errors

Error 5665	Brand name not approved — how to get a brand accepted or list correctly as Generic.
Error 8572	Your GTIN belongs to another brand in GS1 records — the resold-UPC problem, explained and fixed.
Error 8541	Your product matches an existing ASIN but the details conflict — align or list against it.
Invalid GTIN (general)	The umbrella guide to Amazon GTIN rejections and how validation really works.

Google, eBay & Shopify

Merchant Center "Invalid GTIN"	Disapprovals and limited-performance warnings — audit your feed before Google does.
eBay "The UPC you entered is invalid"	Check digit, length and leading-zero problems — and when "Does not apply" is allowed.
Shopify barcode / GTIN errors	Fix invalid barcodes breaking your Google and Facebook channel sync.

Books & publishing

KDP / IngramSpark ISBN rejected

Imprint mismatches, "already in use", format rules — every rejection cause and its fix.

Banking & VAT

"IBAN invalid" on a bank transfer	Typos, O-vs-zero, country length — and why a valid IBAN still isn't proof of an open account.
VIES says "invalid VAT number"	Why a real business fails the VIES check, and what the supplier must do to fix it.
"Invalid routing number"	ACH, wire and direct-deposit routing errors — the checksum banks apply, explained.