Selling on Amazon, eBay, Walmart, and Etsy at the same time means managing different barcode requirements across four different systems. The good news: the underlying codes are the same. One UPC and EAN bundle from UPCBay works across every major marketplace.
Why Barcodes Are the Same Across Marketplaces
UPCs and EANs are universal product identifiers — that's the whole point of the standard. The code you use to create an Amazon listing is the same code Walmart uses to verify your product, and the same code that appears on shelf in retail stores worldwide. You buy one code per variant, and it works everywhere.
Each marketplace has its own internal system (Amazon uses ASINs, Walmart uses WMT IDs, eBay uses its own catalog), but all of them accept the underlying GTIN as the entry point. Your UPC is the key that unlocks the catalog on every platform.
Platform-by-Platform Breakdown
Amazon
Requires a valid UPC or EAN for most product categories. Use your GTIN when creating the listing. Amazon will assign an ASIN. For FBA, you also need FNSKU labels on the physical product — these are generated by Amazon and printed by you.
eBay
eBay strongly prefers listings with valid GTINs. Products without barcodes receive lower visibility in search. Use the same UPC you bought for Amazon — eBay accepts UPC-A (12-digit) and EAN-13 (13-digit). eBay's catalog matching will auto-fill some product details if the GTIN is recognized.
Walmart Marketplace
Walmart requires GTINs for all product submissions. They're stricter than Amazon and eBay — invalid or duplicate codes are rejected outright. UPCBay's registered-prefix codes pass Walmart's verification.
Etsy
Etsy doesn't require barcodes, but adding a UPC to your listing improves visibility in Google Shopping. If you're selling handmade items, Etsy offers GTIN exemptions. For manufactured products, a UPC is recommended.
Shopify
Shopify stores are your own site, so barcodes are optional for the store itself. However, if you use Shopify to sync inventory to Amazon, Walmart, or Google Shopping, each product needs a valid GTIN.
How Many Codes Do You Need?
One barcode per unique product variant — regardless of how many platforms you sell on. A blue medium t-shirt is the same product whether it's listed on Amazon or eBay. You use the same UPC on both platforms.
Where confusion arises: some sellers think each platform needs its own code. That is incorrect. The barcode identifies the product, not the sales channel. Buy one bundle that covers all your SKUs, and you're set everywhere.
Multi-Marketplace Checklist
- Buy one UPC per product variant (not per platform)
- Use the same GTIN when listing on Amazon, eBay, Walmart, and others
- Download both UPC and EAN formats — some platforms prefer one over the other
- Keep a spreadsheet mapping each SKU to its assigned GTIN
- For FBA: print FNSKU labels from Amazon Seller Central — different from UPC
Managing Barcodes Across a Large Catalog
If you're selling 50+ SKUs across multiple platforms, barcode management becomes an operations problem. Here's a simple system that works:
- 1.Download your UPCBay bundle. The Excel file has every code in a spreadsheet — one row per code.
- 2.Add columns for: Product Name, SKU, Platform, Date Listed, ASIN (Amazon), and WMT ID (Walmart).
- 3.Assign one UPC to each product variant. Never reuse a code.
- 4.When listing on a new platform, pull the code from your master spreadsheet rather than generating a new one.
Get listed on every marketplace today.
One UPCBay bundle covers all your products across Amazon, eBay, Walmart, and more.
View BundlesFrequently Asked Questions
Do I need different barcodes for different countries?
No. UPC and EAN are global standards. A US-bought UPC works on Amazon US, Amazon UK, Amazon Germany, and every other marketplace worldwide.
What if two of my products accidentally share the same UPC?
This will cause catalog conflicts on Amazon and other platforms — your listing may be suppressed or merged with another product. Always use a unique GTIN per variant and track assignments in a spreadsheet.
Does eBay require GS1-issued barcodes specifically?
No. eBay accepts any valid GTIN. They don't require GS1 membership. UPCBay codes work on eBay without restriction.
Can I use the same barcode for Amazon and my own website?
Yes. Your Shopify or WooCommerce store can use the same UPC you use on Amazon. The barcode identifies the product, not the sales channel.