What Is a Product Code and How to Use It for Your Business

A product code is a unique identifier assigned to a product, serving as its digital fingerprint across systems, warehouses, marketplaces, and checkout registers. For small business owners in e‑commerce and retail, using accurate product codes - often represented visually as a barcode - can dramatically reduce inventory errors, streamline order fulfillment, and simplify listing on marketplaces and POS systems. Businesses that implement proper coding often see inventory accuracy rates improve by up to 30-40 %, cutting losses from mis‑shipments or stockouts.

In this article, you’ll learn about the main types of product codes such as SKU, UPC, EAN, GTIN, and ASIN, why each matters, and how to choose the right one depending on your sales channels. You’ll also discover how product codes support better inventory management, faster marketplace integration, and easier pricing and stock control.

Key benefits of using product codes

• Improved tracking and management of stock across warehouses and sales channels
• Easier or mandatory compliance when selling on marketplaces or international platforms
• Faster and more accurate order processing and fulfillment
• Reduced errors in pricing, returns, and stock reconciliation

By the end of this guide, you’ll understand how to implement product codes effectively in your business, and how they can save time, money, and headaches.

A Stock Keeping Unit (SKU) is an internal product code used by a business to manage its own inventory — tracking stock movement, sales, restocking, and warehouse organization. Unlike external codes such as UPC or EAN, which are standardized for global trade, SKUs are fully customizable and designed to meet your business’s internal processes and organization.

SKUs typically follow a structured alphanumeric format that encodes meaningful attributes: such as product type, brand or model, color or size, material, or other relevant characteristics. For example, a well‑structured SKU for a clothing store might look like:

TSHIRT-BLU-M-COT
where “TSHIRT” signals product type, “BLU” color, “M” size, and “COT” material. Another might be:

LAPTOP-DELL-15-8GB-SSD
indicating type, brand, screen size, RAM, and drive type.

Because SKUs are internal, they differ from external product codes (like UPC/EAN) used for barcodes and marketplace listings. Instead, SKUs are optimized for inventory management software or warehouse management systems, helping organize stock, simplify picking and packing, and track performance or turnover at SKU level.

Best Practices for Creating SKUs

• Use clear, consistent naming conventions that encode key attributes in a predictable order
• Stick to alphanumeric characters; avoid spaces or special symbols to maintain system compatibility
• Keep SKU codes as short as practical while still meaningful, balancing readability and information content
• Design for scalability — make sure your structure can accommodate future product variations or new categories

When integrated into an inventory management platform, good SKU structure enables accurate stock tracking, rapid inventory audits, and easier restocking decisions. A robust SKU system helps retailers keep operations smooth, avoid confusion, and scale efficiently.

A GTIN (Global Trade Item Number) is the global standard identifier used to uniquely identify products in international trade and e‑commerce. It acts as an umbrella identifier encompassing codes like UPC, EAN, JAN, and ISBN - all part of the same GTIN family managed by the standards organization GS1.

GTIN Family Includes: UPC, EAN, JAN, ISBN (Official source: GS1 website)

Each GTIN code uniquely identifies one product variant (size, color, model). It includes a check digit - a final number calculated from the preceding digits - to help barcode readers verify that the code is valid and reduce data entry or scanning errors.

GTINs are especially important for e‑commerce sellers because most major marketplaces (such as Amazon, eBay, Google Shopping and many others) require a valid GTIN for product listings. Without it, your product may be rejected or receive limited visibility.

Using GTINs facilitates international trade and global listing, enables barcode‑based scanning at warehouses and point of sale, and supports product search, comparison, and cataloging across platforms.

By including GTINs in your listings and packaging, you ensure compliance with marketplace requirements, support accurate inventory and sales tracking, and simplify logistics - which helps expand reach, avoid listing problems, and improve customer trust.

The Universal Product Code (UPC) is a widely used 12‑digit barcode that allows products to be scanned at checkout in retail and point-of-sale systems across the U.S., Canada, Australia and other markets. It ensures efficient inventory and sales tracking in brick‑and‑mortar stores and on marketplaces.

There are two main UPC variants: UPC‑A, which uses the full 12‑digit code and is standard for general retail items, and UPC‑E, a shortened 6‑digit version used for smaller packages where printing space is limited (e.g., cosmetics, small hardware items). Use UPC‑E only when size constraints apply and keep UPC‑A for standard retail listings.

To obtain a legitimate UPC, register with GS1 - the global standards body - to receive your company prefix, then assign UPCs to your items. Although third‑party UPC resellers exist, many platforms and retailers reject codes that aren’t registry‑issued, so avoid unofficial sources.

Including a UPC as a barcode on packaging or listings makes your product eligible for major retail channels and marketplaces, and ensures smooth scanning and inventory management.

Important: Always obtain UPCs directly through GS1 to guarantee compliance with marketplace and retailer requirements - third‑party resold UPCs often get flagged or rejected.

The European Article Number (EAN) - also known as the International Article Number - is the standard product code used across Europe, Asia, and many global markets for retail, wholesale, and e‑commerce trade. The most common format, EAN‑13, consists of 13 digits: a country or region prefix, a manufacturer identifier, and an item number, ending with a check digit for validation.

For U.S. businesses selling internationally, converting a 12‑digit UPC to EAN‑13 is simple: you typically just add a leading zero.

Example: UPC 012345678905 → EAN 0012345678905

You need an EAN when listing on European or Asian marketplaces or selling to overseas wholesalers - those regions often require EAN codes rather than UPC. In those cases, retaining both UPC (for North America) and EAN (for global markets) ensures smooth cross‑border trade.

By using EAN codes, merchants can meet marketplace requirements, support international trade compliance, and streamline global distribution and logistics.

The Japan Article Number (JAN) is Japan’s version of the global EAN standard, structured as a 13-digit barcode (JAN-13). Issued by GS1 Japan, JAN codes begin with the country prefix 45 or 49, which distinguishes them in global systems and ensures compatibility with international barcode readers.

Though technically part of the EAN system, a JAN code is required specifically for product listings on Japanese e-commerce marketplaces like Rakuten and Amazon Japan, as well as for B2B trade within the country. If you're entering the Japanese market, securing official JAN codes through GS1 Japan is critical for compliance.

Note: If your product already has an EAN-13 code and you are not manufacturing in Japan, you may not need a separate JAN - but always check local platform requirements before listing.

Pro Tip: Businesses planning entry into the Japanese market should ensure product codes align with local retail and e-commerce regulations to avoid delays or rejections.

An Amazon Standard Identification Number (ASIN) is a unique 10-character alphanumeric code Amazon assigns to every product listed on its marketplace. ASINs are essential for organizing and searching products on Amazon across all categories.

As of October 2025, sellers must provide a valid GTIN (such as a UPC, EAN, or ISBN) when listing new products not already in Amazon’s catalog. If the product already exists on Amazon, you’ll simply match it to the existing ASIN. Amazon auto-generates ASINs for new listings using the GTIN provided.

Books use their ISBN as the ASIN, ensuring consistency in bibliographic records. For non-book products, a GTIN exemption may be requested if your items don’t have barcodes - but this requires brand approval and justification.

Pro Tip: ASINs streamline e-commerce inventory, protect listings from duplication, and help enforce brand integrity across Amazon’s vast marketplace.

Learn more in our Amazon Selling Guide.

In 2025, QR codes have become a mainstream tool for product identification, especially in mobile-first retail and e-commerce environments. These scannable codes instantly connect users to product pages, authentication portals, or digital content—enabling real-time engagement and transparency.

Beyond marketing, QR codes are now widely used for anti-counterfeiting measures, allowing customers to verify product authenticity with a quick scan. They also support automated inventory tracking and smarter logistics when paired with systems like RFID.

Retailers increasingly embed QR codes on packaging to streamline operations and enhance the customer experience—whether it’s accessing manuals, initiating returns, or tracking shipments. This simple but powerful technology strengthens brand trust, reduces fraud, and brings efficiency to global product management.

Different types of product codes serve specific purposes depending on your sales channel, geography, and inventory management needs. To help you quickly identify which code type is right for your business, use the comparison table below:


Which codes does your business need?

• Selling on Amazon? You need a GTIN to get an ASIN.
• Operating in the U.S. retail market? Use UPC codes from GS1.
• Expanding to Europe or Asia? Get EAN or JAN codes respectively.
• Managing your own warehouse? Use SKUs for internal control.
• Targeting multiple channels? You’ll likely need GTIN + SKU.

Check out our marketplace selling guide for tailored code selection strategies based on your business model.

To use official product identifiers like UPC or EAN, businesses must register with GS1, the global authority responsible for issuing standardized product codes. This ensures universal barcode acceptance across retail and e-commerce platforms like Amazon, Walmart, and Google Shopping.

Registration Steps with GS1

1. Visit the GS1 website and create a company account.
2. Select your product range – determine how many unique barcodes (GTINs) you need.
3. Pay the registration fee – based on company size and code volume.
4. Receive your GS1 Company Prefix – use it to generate GTINs for your products.

As of October 2025, GS1 membership pricing starts at $250 for 10 barcodes, with higher tiers for larger businesses ranging up to $2,100+ annually.

Warning: Avoid third-party barcode resellers. Non-GS1 codes may be rejected by Amazon, trigger compliance issues, or cause supply chain errors. Only GS1 codes guarantee legitimacy and global compatibility.

Implementation Best Practices

• Pre-plan your product catalog to estimate how many SKUs and GTINs you’ll need.
• Integrate codes into inventory management systems for real-time tracking and stock visibility.
• Print high-quality barcodes to avoid scanning failures in retail or warehousing environments.
• Verify barcode readability regularly using verification tools or printers that meet ISO/IEC standards.

Free alternative: Small businesses not selling through marketplaces can use internal SKUs instead of purchasing GTINs for inventory management.

Proper code registration and implementation ensure your products remain compliant, traceable, and marketplace-ready across international borders.

Proper use of product codes can boost operational efficiency, error reduction, and data-driven decision‑making. Follow these best practices to get the most value out of your system:

Best Practices Checklist

• Use a standardized naming or numbering convention and stick to it consistently across all products.
• Ensure each product version or variation has a unique product code - never reuse or duplicate codes.
• Integrate codes into your inventory management software or warehouse management system (WMS) for real-time stock visibility.
• Automate scanning and data capture at receipt, storage, picking, and shipping stages to reduce human error.
• Train staff on scanning procedures and code usage to ensure consistency across teams.
• Schedule regular audits to verify that barcodes match product details and are readable, especially before holidays or peak seasons.

Common Mistakes to Avoid

• Using unofficial or “fake” codes - many marketplaces reject non‑GS1 barcodes.
• Having inconsistent formats (e.g. mixing UPCs, EANs, SKUs without clear rules).
• Poor documentation: not recording which code corresponds to which variant or product attribute.
• Failing to integrate codes into enterprise systems - leading to manual data entry and inventory discrepancies.

Tip: If you already use an ERP or WMS, ensure product code fields are populated at product creation and that automated workflows update stock levels immediately on sales, returns, or restock.

By implementing robust code management practices, your business will reduce errors, scale more smoothly, and use code data for better data analysis and forecasting.

When using product codes in sectors like food, pharmaceuticals, electronics, or regulated goods, compliance with regional and industry standards is essential to avoid legal risks, ensure traceability, and meet retailer/wholesale requirements. As of October 2025, supply‑chain transparency, traceability, and accurate labeling are under growing regulatory scrutiny. Below are key compliance areas to keep in mind:

Key Compliance Areas

• Labeling & Packaging Requirements — Products such as food, medicine, cosmetics, or electronics must carry proper codes and labels (e.g. batch number, expiry date, barcode) as per regional regulations (US FDA, EU MDR/CE, etc.).
• Traceability & Supply Chain Transparency — Many industries require that every product be traceable through manufacturing, logistics, and delivery; unique codes help track origin, batch, and movement.
• Manufacturing & Product Safety Standards — For regulated goods (pharma, electronics), product codes must align with manufacturing records, quality controls, and recall capabilities.
• Logistics and Import/Export Compliance — For cross‑border trade, codes must meet customs, tariff, and trade documentation requirements, especially in regions like EU, US, and Asia.
• RFID or Digital Tracking Regulations — Where applicable, radio-frequency identification or digital barcoding must comply with data privacy, export controls, or industry‑specific traceability laws.

Important: Non-compliance with packaging or labeling regulations can lead to fines, product recalls, shipment rejections, or banned listings - undermining brand reputation and incurring heavy costs.

For regulated sectors and compliance details, refer to official regulatory authorities such as the US FDA or EU regulatory bodies. Adhering to standards ensures smooth market access and protects both business and consumer interests.

Using correct product codes isn’t just about compliance - it can significantly streamline operations, reduce errors, and improve profitability, especially for small and medium businesses.

Operational Benefits

• Better inventory accuracy — Codes make stock counts more reliable, reducing risks of stockouts or overstock.
• Faster point‑of‑sale and order processing — With scannable barcodes or UPC/EAN codes, checkout and warehouse picking become quicker and less error‑prone.
• Improved analytics and pricing decisions — With accurate data tied to each product, businesses can analyze sales trends, monitor inventory turnover, and adjust pricing or promotions accordingly.
• Enhanced warehouse and supply chain efficiency — Standardized codes help organize warehouse storage, streamline logistics, and ensure smooth movement through the supply chain.
• Simplified returns and multichannel selling — Product codes allow consistent tracking across online shops, marketplaces and physical stores; facilitates returns, stock reconciliation and cross‑channel inventory management.

Example: An e‑commerce retailer notices that a specific SKU’s inventory keeps causing stockouts. After adopting standardized UPC/EAN codes and integrating them into their warehouse management, they track real sales velocity correctly, adjust reorder thresholds, and eliminate stockouts - increasing sales by 12% over a quarter.

By combining product codes with inventory and analytics tools - such as those offered by Priceva - businesses gain end-to-end visibility of stock, pricing, and performance, which helps scale operations without chaos.

From SKUs and UPCs to GTINs, EANs, JANs, and ASINs, each product code plays a crucial role in modern retail and e-commerce operations. For small and medium-sized businesses, implementing the right codes means better inventory management, accurate pricing, smoother marketplace integration, and improved customer trust. As your business scales, so does the need for a reliable system to track, price, and manage products efficiently.

Priceva makes this easier with automated pricing tools that integrate with your product codes - helping you monitor competitors, optimize margins, and stay agile in an evolving market.

You’ll usually find a product code printed on the packaging barcode label, or on the product itself. If you sell the item, the code is stored in your internal system or provided by the manufacturer/GS1.

No. A product code identifies the model or item type, while a serial number uniquely identifies an individual unit (useful for warranties, returns, or recalls).

Yes. Each variation — e.g. different size, color, or material — should have its own unique code to enable accurate inventory management, sales tracking, and analytics for each variant.

Yes — for internal use (like SKUs). But for global retail standards (e.g. UPC, EAN, GTIN), you must obtain codes from the official issuing body (like GS1). Homemade codes won’t be accepted by retailers or marketplaces.