Inventory glossary

What is UPC code?

A UPC code is a 12-digit barcode number that identifies a specific product and its packaging, used at checkout and for inventory tracking.

For a small Shopify store, a UPC code is what connects your product to barcode scanners, supplier catalogs, and sales channels like Amazon or retail partners. Each variant that is sold separately, such as a size or color, needs its own UPC if you plan to sell through channels that require scanning.

If you print your own barcodes or buy them from suppliers, keep a clean record of which UPC maps to which SKU and variant. Mixing these up causes wrong items to be picked, scanned, or restocked, and makes receiving inventory slower and less accurate.

Example

A candle store sells a 3-wick jar candle in three scents. Each scent is a separate variant with its own SKU, like CANDLE-JAR-VANILLA, and its own UPC code, like 012345678905. When a staff member scans the barcode on a vanilla candle, the system matches it to that exact SKU instead of a different scent.

Common mistakes

  • Using one UPC for multiple variants, which makes scanning and reordering unreliable.
  • Reusing a UPC after discontinuing a product, which confuses historical sales data.
  • Not recording UPCs in product data at all, relying only on internal SKU codes.

UPC code and SteadyShelf

SteadyShelf tracks forecasting and reordering at the SKU and variant level, so accurate UPC-to-SKU mapping in Shopify helps keep receiving and stock counts correct.

SteadyShelf is launching on the Shopify App Store. Join early access to get the install link first.

Related terms

SKU · Variant · Product master data · GTIN

Full inventory glossary

FAQ

Do I need a different UPC for each variant of a product?

Yes. Each size, color, or scent that is sold as its own unit should have its own UPC code, because the UPC identifies the exact item, not the general product line.

Can I make up my own UPC codes for my store?

You can generate internal barcodes for your own use, but official UPC codes must be assigned through GS1 if you want them to work correctly across other retailers and marketplaces.

Let SteadyShelf do this math for every SKU

Order-by dates per supplier, seasonal forecasts and draft POs for your Shopify store. $29/month after a 30-day free trial.

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