SKU
An internal identifier for a stock keeping unit. It is used within a business context and is not, by the term alone, a standardized trade-item identifier.
Product data glossary
An SKU is an internal identifier a business uses for a stock keeping unit.
This definition distinguishes an SKU from a standardized GTIN and a UPC barcode representation. It does not create, look up, validate, or manage an identifier, product, label, or inventory record.
SKU stands for stock keeping unit. GS1 US describes it as an internal product identifier of a stock keeping unit. A business may use an SKU in its own context; the term alone does not establish product identity, code validity, ownership, inventory, availability, or retailer acceptance. Read GS1 US product field definitions.
Three related terms
Related identifiers are not interchangeable.
The terms can appear together in product conversations, but they have different roles. Defining them helps clarify language without assigning a code or determining what a product record should contain.
GTIN
A Global Trade Item Number is a GS1 standard identifier used to uniquely identify trade items. A GTIN is distinct from an internal SKU.
UPC barcode
UPC is commonly used for a barcode format and the number encoded in it. A barcode can represent an identifier; it is not automatically the same thing as an SKU.
Why context matters
An internal label and a standard identifier serve different purposes.
The important distinction
A glossary names the identifier. It does not issue or validate it.
A business can use an SKU as an internal product identifier, while GS1 describes a GTIN as a standardized identifier for trade items. The distinction explains the terms; it does not decide what code belongs to a product, package, label, record, or inventory unit.
Different identifier contexts
A barcode is a representation, not a product decision.
The word “UPC” is often used in barcode conversations. A barcode may encode an identifier, but this page does not determine whether a code is a UPC, whether it is valid, or whether it matches a product, label, record, or retail requirement.
A source note
Common language helps a team distinguish identifiers.
A product conversation may include internal records, standardized identifiers, and barcode representations. Those labels do not determine which code is correct, valid, unique, or ready for a particular product or market.
Keep the identifier and the operational decision separate.
GS1 US identifies SKU as an internal product identifier of a stock keeping unit. GS1 describes GTIN as a standardized identifier for trade items. These references clarify terminology; they do not assign, register, verify, or manage identifiers or product records.
Glossary boundary: This page does not create, assign, validate, look up, register, publish, or manage an SKU, GTIN, UPC, barcode, product, package, label, record, or inventory unit.
What this glossary does not decide
This educational definition does not create, assign, change, validate, look up, register, publish, or manage an SKU, GTIN, UPC, barcode, item, product, package, label, record, variant, inventory unit, or product data; determine code validity, uniqueness, ownership, product identity, regulatory status, label compliance, inventory, availability, pricing, supplier or co-packer suitability, retailer acceptance, or launch readiness; or provide barcode, product-data, inventory, retail, legal, regulatory, food-safety, accounting, tax, financial, procurement, or operational advice.
Source note
References for this definition
These sources support the terminology on this page. They are not a substitute for a business’s own qualified reviewers, records, trading partners, or applicable authorities.
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