Walmart Will Not Place the Order Without This Number

The email from the buyer arrives at 2:14pm on a Tuesday. "We've completed your product review and we'd like to move forward — pending one item. We cannot process your purchase order without valid GS1 barcodes on each SKU. Please confirm your GS1 company prefix and the GTINs assigned to each variant."

You have barcodes on your products. You bought them from a website for $35 and they came as a PDF. You don't have GS1 barcodes. You have digits that look like barcodes but aren't registered to your company. And Walmart's system is about to find out.

What GS1 is and why it matters

GS1 is a nonprofit standards organization. It issues company prefixes — unique number blocks — to manufacturers and brands worldwide. Every legitimate product barcode in the global supply chain traces back to a GS1-issued prefix.

When a retailer's system scans a barcode, it doesn't just check whether the number exists in their product database. It can verify whether the company prefix matches an active GS1 registration. If the prefix doesn't belong to a registered company — or belongs to a different company than the one claiming to sell the product — the validation fails.

Barcodes purchased on eBay or third-party barcode seller websites are recycled numbers, either invalid or previously assigned to another company. They may scan. They will eventually fail verification.

How a GS1 company prefix works

A GS1 company prefix is a block of digits that belongs exclusively to your company. The length of the prefix determines how many unique product numbers you can assign within it.

A 7-digit prefix gives you 100,000 possible products. A 9-digit prefix gives you 1,000 products. A 10-digit prefix gives you 100.

Your full product barcode number — called a GTIN (Global Trade Item Number) — is your company prefix plus a product number you assign, plus a single check digit calculated from the others. You control the product number assignment. If you have a skincare cream in three sizes, each size gets its own product number within your prefix, and therefore its own unique GTIN and barcode.

How to register with GS1

Go to gs1us.org (for US-based companies). The registration process takes about 15 minutes. GS1 charges an initial registration fee and an annual renewal fee. The cost scales with how many products you need to barcode:

• GS1 US Small Business (up to 10 products): ~$250 one-time + ~$50/year
• Up to 100 products: ~$750 one-time + ~$150/year
• Up to 1,000 products: ~$1,500 one-time + ~$300/year

International registrations go through your country's GS1 member organization. Once registered, you receive your company prefix and access to the GS1 Registry where you list your products. You're responsible for assigning product numbers to each of your SKUs — GS1 doesn't do this for you.

Common mistakes that get products pulled

Buying barcodes from a third-party seller. "1,000 unique UPC codes for $20" on eBay are recycled GTINs — either previously registered to another company or never legitimately registered. Major retailers have automated verification systems that flag unregistered prefixes.

Not listing products in the GS1 Registry. Registration gives you the prefix. Listing your products in the GS1 Registry makes them verifiable to retailers and distributors. Skipping this step causes verification failures even with a legitimate prefix.

Reusing GTINs. Each product variant — different size, color, flavor, or formulation — requires its own unique GTIN. A company that reuses the same GTIN for different variants creates tracking chaos for retailers and distributors.

Not renewing annually. A lapsed GS1 registration can cause your prefix to fail verification. Retailers will flag products with an inactive registration. Set a calendar reminder for annual renewal.

After registration: assigning GTINs to your products

Once you have your prefix, work through your product line and assign a product number to each SKU variant. Write these down in a document you won't lose — your GTIN list is a critical business record.

Then generate your barcode labels. Enter each GTIN into MyQR Barcode Generator, choose EAN-13 or UPC-A format, set the dimensions to your label spec, and download. Apply labels to products or integrate into your label design file.

If you're selling through retailers, you'll also provide your GTINs on product data sheets when submitting items for setup. The retailer's system cross-references your GS1 registration as part of onboarding. Make sure the barcode prints at the correct size and scans correctly before submitting.

GS1 and QR codes on the same label

Many brands now include both a UPC barcode (for retail scanning) and a QR code (for customer authentication or product information) on the same label. The QR code for product authentication goes on the front of the label; the UPC on the back or bottom for POS scanning.

GS1 also offers GS1 Digital Link — a specification for encoding GS1 data into a QR code — which allows a single 2D code to serve both retail scanning and customer-facing applications. Adoption is growing; worth implementing if you're designing labels today.