Manage SKU and GTIN/barcode assignments for products across a catalog

Steps

1. Establish a SKU schema for your catalog (e.g., BRAND-CATEGORY-STYLE-SIZE-COLOR) and enforce it through a master product database before pushing to any sales channel
2. Assign GTINs (UPCs, EANs, or ISBNs) to each unique product variant; acquire GS1-registered GTINs from gs1.org if you manufacture products, or source existing GTINs from supplier data sheets for resale items
3. Store SKU-to-GTIN mappings in a central lookup table; use this table as the authoritative source when creating listings on eBay, Amazon, Walmart, and Google Shopping, all of which require GTINs
4. Validate GTIN check digits programmatically before submission using the standard GS1 check digit algorithm to prevent rejection errors from marketplaces
5. For bundles or kits that do not have a manufacturer GTIN, either apply for a bundle GTIN or use the channel's exemption process (e.g., eBay GTIN exemption request, Amazon bundle exception)
6. Sync SKU/GTIN data to your shipping software so barcode scanners at the fulfillment center can correctly identify and pick items without manual lookup