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SKU, GTIN, EAN, ASIN, ISBN, UPC, Code128: Meaning and Differences Between Them

SKU, GTIN, EAN, ASIN, ISBN, UPC, Code128: Meaning and Differences Between Them

In the modern and dynamic world of ecommerce and global trade networks, unique product identifiers play a crucial role in efficiently managing and controlling product assortments. They are an indispensable tool that enables the accurate identification of products, their traceability throughout their lifecycle, and the optimization of business processes.

We provide an overview of the most important unique product identifiers and their role in increasing the efficiency of business operations.

What is SKU?

SKU (Stock Keeping Unit) – a unique identifier assigned to each product in a warehouse or retail store for unique identification and tracking.

The SKU concept was developed to facilitate inventory management and allow companies to efficiently monitor, track and manage their product inventory. Each SKU consists of a unique combination of letters, numbers and symbols specific to each product in the company. This enables accurate product identification and helps avoid confusion during order processing and inventory management.

The importance of SKU in inventory and sales management

SKU plays a critical role in inventory and sales management and offers the following benefits:

1. Product Identification: Each product in the warehouse or store has its unique SKU, which facilitates tracking and identification. This allows for quickly determining the availability of a product in the warehouse or store and simplifies the search for the desired product.

2. Inventory Management and Control: SKU is used for inventory management in the warehouse. When a product arrives in the warehouse, it is assigned a unique SKU, which is then entered into the inventory system. This enables real-time tracking of product quantities in the warehouse and optimization of inventory.

3. Order Processing: SKU plays a crucial role in the order processing process. When a customer places an order, employees can quickly identify the product by its SKU, speeding up and simplifying the assembly and shipping process.

4. Assortment Management: SKU allows for more efficient assortment management. Analyzing data by SKU helps determine which products have the highest demand and which are less popular. This aids in making informed decisions about product offerings.

5. Inventory Simplification: SKU greatly simplifies the counting and verification of products in the warehouse during inventory checks. Instead of using traditional product names, employees can use SKU for product identification and counting, reducing the likelihood of errors and increasing inventory accuracy.

GTIN, EAN and UPC: meaning and differences

GTIN, EAN and UPC are three important product identification standards that play an important role in modern global trade and e-commerce. They are unique codes that can be used to accurately identify and distinguish each product on the international market.

What is GTIN?

GTIN (Global Trade Item Number) is a global product identification standard used for the unique labelling of products and packaging. The GTIN is a numeric identifier that allows products to be accurately identified and distinguished from each other. It is a key element of the Unique Product Identifier system and is used in various industries and companies worldwide.

What is the difference between GTIN and EAN?

EAN (European Article Number) is a European barcode standard used to encode the GTIN on product packaging. EAN is a subset of GTIN and consists of a unique 13-digit barcode that contains information about the country of manufacture, the manufacturer and the specific product.

The main difference between GTIN and EAN is the structure and barcode format. The GTIN includes different formats such as GTIN-12 (12 digits), GTIN-13 (13 digits) and GTIN-14 (14 digits). Leading zeros are added to GTIN-12 and GTIN-13 to ensure a consistent format. EAN is a special 13-digit barcode format that does not include leading zeros.

Despite these minor differences, both GTIN and EAN serve the purpose of ensuring the unique identification of products and improving administrative and commercial processes in the global e-commerce market.

What is UPC?

UPC (Universal Product Code) is an American barcode standard developed to encode the GTIN on products sold in the USA and Canada. UPC consists of 12 digits and is another subset of GTIN. Similar to EAN, UPC is a unique barcode that identifies a product and its manufacturer.

It is important to know that GTIN, EAN and UPC are interchangeable identifiers, which means that the same product can be marked with different codes depending on the sales region. This allows manufacturers and sellers to use universal standards to code products and ensure international product identification.

What is Code128?

Code128 is a barcode standard that differs significantly from widely used standards such as EAN and UPC.

This barcode type not only allows the encoding of numbers, but also of letters of the Latin alphabet as well as special characters. Code128 is one of the most flexible and versatile standards for product identification and is therefore particularly suitable for situations where large amounts of data need to be represented.

Code128 offers a number of advantages that make it particularly attractive for companies:

1. Support for a wide range of data

Code128 enables the encoding of large amounts of data, including numbers, letters and special characters. This is particularly important when additional product information such as date of manufacture, expiry date or batch number needs to be represented.

2. Unique coding

Each character in Code128 has its own unique structure, making it a reliable identifier for products and processes. This helps to avoid errors and confusion when scanning barcodes.

3. Versatility

Code128 is used in various industries and business sectors. From logistics and warehouse management to the medical and pharmaceutical industries, this barcode standard is used in a variety of business processes.

4. Accuracy and scanning speed

Due to its special structure, Code128 ensures high scanning speed and accuracy, which increases employee efficiency and reduces the likelihood of errors.

What is ISBN?

The ISBN (International Standard Book Number) is a unique identification number for books. Thanks to this unique identification number, each book can be uniquely identified and tracked in inventory systems. This facilitates the inventory, sale and distribution of books in the global market.

The ISBN (International Standard Book Number) also contributes to transparency in the book trade by simplifying the ordering and delivery procedures for books between publishers, retailers, bookshops and libraries. Each edition of a book, whether printed or electronic, must have a unique ISBN to ensure proper identification and reporting.

The Structure of ISBN

A standard ISBN consists of 13 digits divided into five parts, with each part providing specific information about the book:

1. Prefix: Typically “978” or “979,” indicating that it is an ISBN for a book.

2. Group Identifier: This number determines the country or region where the book was published.

3. Publisher Identifier: This number indicates the specific publisher of the book.

4. Edition Identifier: This number identifies the specific edition of the book, including format and edition.

5. Check Digit: This is the final digit of the ISBN, used to verify the accuracy of the other digits.


The ISBN standard is compatible with EAN, allowing EAN to be used for encoding the ISBN of a book. This simplifies the integration of books into inventory management systems that rely on EAN coding and ensures a unified approach to product identification, including books, in the global market.

What is ASIN?

ASIN (Amazon Standard Identification Number) is a unique product identification number used on the Amazon platform. Every product listed on this largest online marketplace is assigned a unique ASIN. This number plays a crucial role in the process of identifying and categorizing products on Amazon, making it easier for customers to search and compare products for purchase.

ASIN consists of 10 characters, including Latin letters and digits. It’s important to note that it’s not possible to independently create an ASIN on Amazon. When a product is introduced into the Amazon system, it automatically receives its unique ASIN.

ASIN and its Relationship with GTIN or EAN

ASIN is closely related to GTIN and EAN. In the past, Amazon allowed the creation of ASINs without specifying GTIN or EAN, which allowed some sellers to use fake identifiers. However, Amazon has changed its policy to improve the accuracy and reliability of product information and now requires genuine GTIN or EAN to be provided to create an ASIN.

This means that every product introduced on Amazon must be linked to its unique identification number, such as GTIN or EAN, before it can receive its ASIN and be listed for sale on the platform.

The role of unique identifiers in online marketplace sales

The importance of unique product identifiers for sales on marketplaces cannot be overstated, as they play a crucial role in ensuring the efficiency, transparency and reliability of trade transactions. They contribute to better inventory management, building trust among customers and the overall success of both sellers and e-commerce platforms.

Here are some aspects that show why unique identifiers are an indispensable component for successful sales on marketplaces:

1. Uniqueness and Precise Product Identification

Unique identifiers such as GTIN, EAN, UPC, and ASIN are assigned to each individual product. This allows for the precise identification of each product among millions of items on marketplaces and prevents the possibility of duplicates or confusion between different products.

2. Combating Counterfeits and Ensuring Quality

Unique identifiers assist in combating counterfeit products as they enable tracking and verification of the authenticity of goods. They also contribute to ensuring high product quality as sellers are obligated to provide accurate product identification.

3. Efficient Inventory Management

The use of unique identifiers simplifies inventory management and logistical processes on marketplaces. Sellers can track inventory accurately, avoid shortages or overstocking, thereby enhancing the efficiency of their business processes.

4. International Standardization

Global identification standards like EAN and UPC provide a uniform format for information exchange with partners and global e-commerce platforms. This promotes better compatibility and facilitates logistics and inventory management processes.

5. Enhanced User Experience

For buyers, unique identifiers ensure accuracy and reliability when searching for and selecting products. Customers can easily find identical products, compare their features, and compare offers on different marketplaces, leading to a better user experience and higher customer satisfaction.

6. Compatibility with Platforms and Marketplace Requirements

Many marketplaces require the presence of unique product identifiers to create listings and sell on their platform. By meeting these requirements, sellers can easily list their products on various marketplaces and expand their market.

As mentioned earlier, Amazon didn’t pay sufficient attention to the authenticity verification of identifiers in the past, leading to the possibility of some sellers using fake GTINs or EANs. However, GTINs and EANs are now rigorously checked on the platform when provided by sellers. That’s why it’s crucial for every seller to track the unique identifiers of their products in their inventory system and use only real and valid codes. This helps to avoid potential issues when selling on marketplaces and ensures compliance with platform requirements.

How Ysell.pro does a unique ID track?

Ysell.pro provides powerful tools for tracking unique product identifiers such as GTIN, EAN, ISBN, and UPC.

When creating a new product in Ysell, the system offers the option to enter the relevant unique identifiers in the “Manufacturer Number” field. This allows you to associate the product with its unique code, ensuring accuracy in identification.

When scanning goods in the warehouse or receiving new shipments, the system utilizes the stored unique identifiers to precisely identify each product based on its corresponding GTIN, EAN, ISBN, or UPC code. This approach ensures high reliability and accuracy in inventory management while preventing potential errors or mix-ups among different products.

Additionally, Ysell provides the capability to analyze and manage products on the Amazon platform using ASIN, SKU, and FNSKU codes. Through their close integration with Amazon products, Ysell allows for the collection and analysis of sales statistics, including sales volume, Amazon referral fees, and the calculation of Return on Investment (ROI) for each unique identifier.

This offers valuable insights to sellers regarding the performance of each product, enabling them to make informed decisions and optimize sales strategies on the platform.

When creating shipments on Amazon through Ysell, ASIN and SKU are used to generate FBA shipments. This ensures efficient inventory management and logistics, making it easy for sellers to track and manage their products on the platform.

Indeed, Ysell.pro provides all the necessary tools for tracking and managing unique product identifiers, ensuring high accuracy, efficiency, and user-friendliness in inventory management and sales on various platforms, including Amazon.

Frequently Asked Questions

1. Can the same GTIN or EAN be used for different variants of a product?

No, each product variant with unique characteristics should have its own GTIN or EAN. This allows for the precise identification of each product variant and prevents confusion among buyers and inventory management systems.

2. Can the unique identifiers be changed or updated during the product’s lifecycle?

No, you must not change or update unique identifiers such as GTIN, EAN and ISBN once they have been assigned. They must remain unchanged throughout the product’s lifecycle and be used for product identification in all sales and delivery stages.

3. What can be the consequences of using incorrect or inappropriate unique identifiers?

Using incorrect or inappropriate unique identifiers can lead to errors in inventory management, confusion among buyers, and potentially issues with selling on marketplaces and platforms.


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