Most barcode problems come down to a handful of avoidable mistakes. Here are the big ones and how to dodge them.
Reuse and duplicates
Using one number on multiple products — or a number already assigned elsewhere — triggers duplicate errors and removals. One unique number per product, always.
This is the single most common cause of rejection.
Format and image errors
A wrong length, bad check digit, or a low-resolution/cropped barcode image fails validation or scanning. Validate the number and test the image before listing.
Keep quiet-zone margins and print at high resolution.
Details and records
A brand mismatch between your listing and the GTIN can flag gated categories. And without a record of which number maps to which product, errors creep in as you scale.
Keep a simple master sheet and verify before you list.
Frequently Asked Questions
What’s the most common mistake?
Reusing a number across products or using one already assigned.
How do I avoid format errors?
Validate the number and test the barcode image before listing.
Do I really need records?
Yes — a number-to-product map prevents duplicates as you grow.
Avoid the duplicate trap: get genuine, never-previously-used numbers at GoodUPC, and check any code with our validator.