What is Unique Identification Number

A unique identification number is a code assigned to a product, item, or entity to distinguish it from all others. It’s used to track, manage, and identify things accurately across systems, channels, or databases. Common examples include GTINs, UPCs, and ISBNs.

Examples

Format Example Notes
GTIN-13 5412345678907 Common in Europe and used for retail products (EAN format).
UPC-A 012345678905 Standard 12-digit code used in North America.
ISBN-13 9780306406157 Used globally to identify books and other publications.
MPN ABC123XYZ Manufacturer-assigned code for tracking specific products.
ASIN B08N5WRWNW Unique Amazon identifier used to list and track products.

Good to know

Not all unique identification numbers are created equal. Some like GTINs or UPCs are standardized and managed by global organizations, while others like MPNs or ASINs are created by manufacturers or platforms for internal tracking.

It’s important to know which ones your channels or partners require, and to stay consistent in how you use them across systems. A clear, centralized approach helps avoid mix-ups and ensures your products are accurately identified everywhere they appear.

Know more

Frequently Asked Questions

What counts as a unique identification number for a product?
A unique identification number is any code used to identify a specific product. Some of the most common types include: GTINs, such as UPCs and EANs, which are globally recognized barcodes ISBNs for books MPNs (Manufacturer Part Numbers), often used in industrial or tech products ASINs on Amazon These numbers vary by industry and channel, but they all serve the same basic function: to uniquely identify a product.
Do I need more than one identification number?
Possibly. Some products may use one number internally (like an MPN) and another externally (like a GTIN). Different platforms or marketplaces often require specific formats, so it’s common for a single product to have multiple identifiers depending on where it’s listed.
What’s the difference between a GTIN, UPC, and EAN?
GTIN is the umbrella term. A UPC (12 digits) and an EAN (typically 13 digits) are both types of GTINs. Which one you use often depends on your region or retailer requirements. UPCs are common in North America, while EANs are more widely used globally.
Can I create my own unique identification numbers?
It depends on where and how your product will be sold. For internal use or on your own website, yes, you can create your own codes like SKUs or MPNs. But for selling on marketplaces (like Amazon) or in retail stores, you'll likely need globally recognized identifiers like GTINs, which GS1 assigns.
What happens if two products have the same identification number?
That’s a problem. Unique identification numbers are meant to be just that unique. If two products share the same code, it can cause listing errors, inventory issues, or even compliance problems with retailers. Always make sure each item has a distinct identifier that matches across your systems and channels.