Do You Need Barcodes to Sell Online? GS1 vs SKU Codes

“Do I need a barcode?” is one of the most common questions new sellers ask – and the answer depends on where you sell and what the barcode is for. There are two different jobs: identifying your product to marketplaces and retailers, and tracking it in your own stock. They need different kinds of codes.

Two kinds of barcode

• GS1 barcode (GTIN) – a globally unique product number (UPC in North America, EAN elsewhere) licensed from GS1 and registered to your company. Marketplaces and retailers use it to identify the product.
• Internal SKU barcode – your own stock-keeping code printed as a barcode, typically Code 128. Only your systems read it, so you can create it yourself for free.

Many sellers use both: the GTIN for channels that require it, and SKU barcodes for shelves, bins, bundles and products that have no GTIN.

Where a GS1 barcode is needed

• Amazon – new listings in most categories need a GTIN, and Amazon checks it against GS1 data. If your products genuinely have no GTIN (for example handmade, private label or generic items), you can apply for a GTIN exemption in Seller Central; it is granted per brand and category.
• Walmart Marketplace and physical retail chains – buyers expect GS1-registered numbers.
• Google Shopping – a correct GTIN helps your products match and show properly.
• Wholesale – distributors usually pass retailer requirements on to you.

Where it is optional

• Shopify and WooCommerce stores – the barcode field is optional. It matters once you use a POS, sync to Google Shopping or sell wholesale.
• Etsy – your own SKUs are enough.
• eBay – you can select “Does not apply” where no product ID exists.
• Internal inventory – shelves, bins, warehouse locations and assets never need GS1 numbers.

Marketplace rules change, so always check the current requirements of each channel before you list.

A simple setup that works everywhere

1. Give every product and variant a SKU with a consistent pattern – category, model, colour, size. The free SKU generator builds them in bulk.
2. Add GTINs where a channel requires them and store them next to the SKU in your catalogue.
3. Print a barcode label for every product that has no scannable code yet – the SKU in Code 128 is fine for your own stock.
4. Label your locations too with the location code generator, so every count has an address.
5. Keep one product = one code in your system. Whatever is scanned – GTIN or SKU – must point to the same item.

Scanning them with WiScanner

Once your products carry barcodes, a phone is all you need to use them every day:

• Count stock with groups per shelf, live running totals and Quantity Scan for full cartons – see the inventory counting app.
• Scan into any app on a paired PC or Mac – Excel, your ERP or a marketplace upload sheet.
• Pick and fulfill by scanning and keep stock aligned across Shopify, WooCommerce, Etsy, ikas and Lightfunnels with Pro.
• Start free – 100 scans with every scanning feature, then scan packs or Pro.

Retail is also moving to 2D barcodes – read GS1 Sunrise 2027. Sources: GS1, Amazon Seller Central help on GTIN exemptions, marketplace seller guides.