What is a Universal Product Code: How They Work & How to Get UPC Codes

A Universal Product Code (UPC) is the 12‑digit North American product identification standard used to uniquely identify consumer goods in retail environments. Represented as a barcode on packaging, a UPC enables fast, accurate scanning at point of sale, inventory management, and seamless integration across physical stores and online marketplaces. In North America, the only legitimate source of UPCs is GS1, the global authority that assigns and manages standardized product identifiers.

Manufacturers, brand owners, retailers, and e‑commerce sellers are often required by major marketplaces and big‑box retailers to include a valid UPC on every item they sell. UPCs are essential for listing products on platforms like Walmart, Target, and online marketplaces, ensuring your products are discoverable, trackable, and compliant with retail systems.

A Universal Product Code (UPC) is a 12-digit code used to uniquely identify products in North American retail. It appears on packaging as a barcode, which can be scanned by point‑of‑sale systems to instantly retrieve product information. UPCs are a core element of modern product identification, enabling faster checkout, accurate pricing, and efficient inventory management across physical stores and online channels.

UPCs are issued and governed by GS1, a nonprofit, global standards organization responsible for maintaining product identification systems worldwide. GS1 ensures that every UPC is globally unique and traceable to a legitimate brand owner, which is why major retailers and marketplaces require GS1‑issued codes. While UPCs are standard in the U.S. and Canada, other regions commonly use international GS1 standards such as EANs. If you plan to sell in North America, obtaining a UPC through GS1 is essential for compliance, scalability, and long‑term brand credibility.

Learn more - visit GS1 directly at https://www.gs1.org.

A UPC barcode is composed of a series of vertical bars and spaces that encode a 12-digit numerical code. Each digit is represented by a unique pattern of bars and spaces, with varying widths ranging from one to four modules wide. These patterns are read by barcode scanners, allowing for fast and accurate product identification at checkout and during inventory tracking.

A UPC is divided into three main parts:
1) Manufacturer Identification Number (first 6 digits) – Assigned by GS1 when a company registers, this portion identifies the brand or manufacturer responsible for the product.

2) Product Code (next 5 digits) – Chosen by the company, this code differentiates products by attributes such as size, color, or flavor. Each variation must have a unique code. For example, a black size XS shirt will differ from a black size XL shirt.

3) Check Digit (final digit) – A mathematically derived number used to verify the code’s accuracy during scanning.

Companies must ensure product codes are unique and not reused, even for discontinued items, to maintain database integrity and prevent fulfillment issues.

The check digit is the 12th and final number in a UPC. It functions as a built-in validation tool to ensure that the barcode has been entered or scanned correctly. This is crucial for catching transposition errors or single-digit mistakes.

It is calculated using a modulo-10 algorithm based on the first 11 digits:

1. Add digits in odd positions (1st, 3rd, etc.), then multiply by 3
2. Add digits in even positions (2nd, 4th, etc.)
3. Add results from steps 1 and 2
4. Find the nearest higher multiple of 10
5. Subtract the step 3 total from this multiple — that’s your check digit

Example: For UPC 03600029145, the check digit is 2, making the full code 036000291452.

Scanners instantly recalculate this digit and reject the barcode if it doesn't match — a powerful tool for error detection.

Not all UPCs look the same - some are 12 digits long, while others are compressed into just 8 digits. Both formats serve different use cases in retail and inventory management.

The UPC-A is the standard 12-digit barcode used in North American retail. It encodes a full GTIN-12 (Global Trade Item Number), making it ideal for most products sold in physical stores and online. This format is the most commonly recognized and supports detailed product tracking.

The UPC-E is a compressed version with only 8 digits, designed for small packages with limited space, such as cosmetics, gum, or small accessories. It still encodes a full GTIN-12 by compressing zeroes in the number and is fully compatible with standard barcode scanners.

The ISBN (International Standard Book Number) is a 13-digit code used globally to identify books and other publications. To integrate with retail systems, it is encoded using the Bookland EAN system, which adds a 978 or 979 prefix to convert the ISBN into a barcode that can be read like a standard UPC.

An ISBN consists of four parts: the prefix, registrant (publisher), publication identifier, and a check digit. For retail, it is often displayed alongside or embedded within a UPC-format barcode on the back cover.

Example: ISBN 978-0-123456-78-9 is converted for retail using the EAN system and scanned just like a traditional UPC.

This dual system ensures books are globally recognized yet remain compatible with North American retail scanners.

Obtaining a legitimate Universal Product Code (UPC) isn’t something you can improvise — it must be done through the official global standards body responsible for product identification. That organization is GS1, a nonprofit that manages UPC and barcode standards worldwide, issues company prefixes needed for creating legitimate UPC codes, and maintains global standards for product identification. Working through GS1 ensures your UPCs are unique, compliant, and accepted by retailers, marketplaces, and supply chains globally.

A UPC begins with a company prefix, a unique identifier that GS1 assigns to your business. This prefix forms the first part of every UPC you issue and ties your products to your brand in retail systems.

GS1 Company Prefix Fee Structure

Processing time: After your application is approved, GS1 typically issues your prefix within 1–2 business days once payment is complete.


Annual renewal: Your prefix and the associated UPCs must be renewed each year to remain valid and avoid revocation.

Once you have your GS1 company prefix, you assign a unique product number to each SKU. Each variation (size, color, flavor) needs its own five‑digit code. When combined with your prefix plus the calculated check digit, this forms a valid UPC.

Barcodes must be placed on packaging where they are easily scannable — contrasting bars and spaces are critical. If packaging is not yet finalized, obtain a digital barcode file from GS1 and integrate it into your design. This ensures readability on shelves and at checkout.

While GS1 issues UPCs, it does not handle design or printing. You can integrate barcodes into your packaging artwork yourself or use third‑party services. Best practices include placing barcodes where scanners clearly read them, considering separate labels for inner and outer packaging, and testing scans before distribution.

Universal Product Codes (UPCs) offer measurable benefits across the entire retail, inventory management, and supply chain lifecycle.

Here are five key advantages:
Faster Checkout

• UPC barcodes streamline point-of-sale (POS) systems, reducing average checkout time by up to 40% compared to manual entry.
• Scanners read product data instantly, minimizing customer wait times and cashier errors.

Inventory Accuracy

• Real-time scanning enables precise inventory tracking, helping prevent both overstock and stockouts.
• Integration with tools like Priceva’s inventory monitoring system ensures product counts remain accurate across channels.

Supply Chain Visibility

• UPCs allow retailers to trace products from manufacturer to store shelf.
• This traceability helps detect recall risks, identify shrinkage points, and optimize distribution.

Automated Reordering

• Sales data tied to UPCs can trigger automated restock alerts, improving efficiency.
• Smart systems predict replenishment needs based on sell-through velocity.

Error Reduction

• By eliminating manual price entries, UPCs reduce pricing errors at checkout and in labeling by over 95%.
• Accurate scanning supports price integrity and boosts customer trust.

Ready to enhance your pricing and barcode strategies? Explore Priceva’s price tracking tools to keep your product data aligned across platforms.

Both Stock Keeping Units (SKUs) and Universal Product Codes (UPCs) are essential tools in retail, but they serve very different purposes. A SKU is an internal code used by individual retailers for inventory tracking and store operations. A UPC, by contrast, is a standardized 12-digit barcode issued by GS1 for universal product identification across retailers, marketplaces, and supply chains.

Comparison Table: SKU vs. UPC

Real-World Example
Imagine a white T-shirt, size M, sold by three retailers. All three stores use the same UPC (e.g., 123456789012) for universal identification. However, each assigns their own SKU:

• Retailer A: TSHIRT-WHT-M-001
• Retailer B: WHT-MED-T100
• Retailer C: TWM23A

All refer to the same product, but each SKU is unique to the store’s inventory system.

When to Use Each
Use SKUs to manage internal operations: shelf placement, restocking, reporting. Use UPCs to meet retail, marketplace, and distributor requirements. Together, they enable precise inventory tracking, sales analytics, and operational efficiency.

A Global Trade Item Number (GTIN) is a family of globally recognized product identifiers managed by GS1, used to uniquely identify trade items in retail, logistics, and e-commerce. A UPC is one specific type of GTIN — more precisely, GTIN-12, the 12-digit format used predominantly in North America.

All UPCs are GTINs — but not all GTINs are UPCs.

GTIN is the umbrella term. It includes various formats depending on the use case, digit length, and region. Below is a breakdown of GTIN formats:

Why This Matters
Retailers and marketplaces (like Amazon or Walmart) require a GTIN to list a product. Depending on your market, this might mean submitting a UPC (GTIN-12) or EAN (GTIN-13). Global compatibility and platform compliance depend on using the right format.

When You’ll See GTIN Terminology
You’ll often encounter GTIN in application forms, data templates, and API documentation. It’s the formal term used by GS1 and e-commerce platforms when referencing product identification standards across regions.

The Universal Product Code (UPC) and the International Article Number (EAN) are both barcode formats standardized by GS1 for retail and global commerce. While they serve the same core purpose—product identification and inventory tracking—they differ slightly in structure and regional use.

Barcode Structure: 12 vs. 13 Digits
A UPC contains 12 digits and is widely used in the United States and Canada. An EAN, also known as International Article Number, contains 13 digits and is standard worldwide, especially in Europe, Asia, and Latin America.


Country Code Prefix
The first digits of an EAN indicate the GS1 member organization country, such as:

• 400–440: Germany
• 690–695: China
• 50: United Kingdom (In contrast, UPCs typically begin with a 0 and imply U.S. origin)

UPC to EAN Conversion
To convert a UPC to an EAN, simply add a leading zero to make it 13 digits. This ensures compatibility across global databases and scanning systems.

When It Matters
If you sell products internationally or on global marketplaces like Amazon or Walmart, EANs ensure broader recognition, while UPCs remain essential for North American retail.

If you are going to launch an online or brick-and-mortar store, make sure to obtain UPC codes for your products legitimately by applying to GS1. That will enable you to sell on marketplaces, your own website or other stores both in the U.S. and internationally.

Aside from that, a UPC code makes it easy to track your products if you distribute them through resellers. For example, you can use Priceva’s price tracker or MAP monitoring tools that will enable you to get real-time pricing information, and set them up to search for your products by parsing their UPCs.

The check digit is the 12th digit of a Universal Product Code (UPC) and ensures accuracy by validating the preceding numbers. It’s calculated using a modulo‑10 algorithm that helps detect scanning or data entry errors by barcode readers.

Calculation steps:

1. Add digits in odd positions (1st, 3rd, etc.)
2. Multiply that sum by 3
3. Add digits in even positions
4. Combine totals
5. The check digit is the number that brings the total up to the next multiple of 10

Example: For UPC base 03600029145, the check digit becomes 2. Barcode scanners automatically validate this and reject mismatches.

A Global Trade Item Number (GTIN) is an umbrella term managed by GS1 that includes product identifiers like UPC, EAN, and others. All UPCs are GTINs (specifically GTIN‑12), but not all GTINs are UPCs — formats also include GTIN‑8, GTIN‑13, and GTIN‑14. When platforms request a GTIN, sellers can typically provide the UPC code.

GS1 is the global standards organization that issues legitimate company prefixes and maintains the database used by retailers to verify UPC authenticity. Buying resold UPCs presents compliance risks: major marketplaces may reject listings, suspend accounts, or remove products because resold codes may already be tied to other products. Resold codes have unpredictable histories and may conflict with existing assignments, making them unreliable for retail systems. Always purchase codes directly from GS1.

Yes—UPCs are recognized globally and work across countries, even though UPC is a North American standard. The same UPC can identify the same product worldwide. In some regions, systems prefer EAN‑13 format (UPC with a leading zero), but underlying identification remains consistent. GS1 manages these standards to ensure cross‑border compatibility in retail and marketplace systems.

No. A Universal Product Code remains valid permanently once issued by GS1. However, companies must maintain active GS1 membership to avoid verification issues with retailers. UPCs should never be reused after a product is discontinued, as recycling codes can confuse historical data and inventory systems. Some retailers check membership status when onboarding products, so lapses may affect new listings.