Barcode ABCs For Small E-commerce Businesses

Barcodes are everywhere, because they’re incredibly useful. They’re on objects all around us, from cereal packets to airline boarding passes; and in every setting from grocery stores to hospitals. They’re a simple and efficient way to track and manage inventory, streamline operations, prevent errors and even, thanks to increased speed and accessibility, enhance customer satisfaction.

There are many different types of barcodes, though, and the right choice makes all the difference. For example, if you’ve ever felt frustrated at a self-checkout, chances are there was a poor choice of barcode involved. So here’s our beginner’s guide to barcodes, with extra references in case you want to know more.

The Main Barcode Types

For each barcode format, a set of rules called a symbology defines what characters it can represent, and how. There are dozens of barcode symbologies in use around the world, many of them only seen in very specialized contexts like blood banks, postal services or print shops. In this article we’ll focus on the more common types — but if you want to dive deep into the world of Flattermarken, LOGMARs and Telepen, Austrian barcode software company TEC-IT has the most comprehensive barcode overview we’ve found.  

1D Barcodes

Linear or one-dimensional barcodes are the most common barcode type. They’re made of vertical parallel lines and spaces of varying widths, each representing a character or digit. The good old cereal box barcode is one of these. 

Linear barcodes enable quick and accurate reading of small amounts of data, like product identification numbers or pricing information. They are ideal for applications where simplicity and speed are essential, like retail point-of-sale systems and inventory management.

They’re sometimes called standard barcodes. But as this article demonstrates, there’s really no such thing as a standard barcode, only an appropriate barcode for the job. 

Some of the most widely used 1D barcodes are:

Code 39

Code 39 barcodes are very simple, originally representing just the 26 letters of the English alphabet, the digits 0-9 and a handful of special characters. It has a couple of cousins, Code 39 Extended and Code 93, which are able to encode more characters in a smaller space. Code 39 Extended, for example, uses the full ASCII set of 128 characters, including upper- and lowercase letters and a full set of special characters.

Each code contains:

1. Start and stop characters: An asterisk (*) marks the beginning and end. This is usually not included in the human-readable text below the barcode, but is visible to scanners.
2. Data characters: Alphanumeric characters, including some special symbols.
3. Inter-character gap: A small space between each character for separation.
4. Check digit: Optional, for extra accuracy.

Code 128

Code 128 uses the full ASCII character set, and does so more efficiently than Code 39. It’s widely used around the world, especially for package tracking.

Each code contains the following elements (not all of which are visible in the human-readable text):

1. Start code: Defines the character set being used (A, B, or C).
2. Data characters: Alphanumeric or numeric-only, depending on the character set.
3. Check character: Calculated from the data characters for accuracy.
4. Stop code: Marks the end of the barcode.
5. Quiet zone: Empty space on either side, for clean scanning.

UPC barcodes

Universal Product Code (UPC) is the go-to barcode type in the US and Canada.  UPC-A barcodes are 12 digits long, while UPC-E is a shorter, 8-digit version. Both, along with a bunch of specialist subcodes, are widely used for inventory tracking of retail products. 

Each UPC consists of three parts:

1. Manufacturer ID: The first set of numbers identifies the maker.
2. Product ID: The second set is for the specific item.
3. Check Digit: The last digit ensures the code is scanned correctly.

Unline Code 39 and Code 128, where the data characters can stand for any information you want, UPCs specifically encode manufacturer and production information. 

UPC barcodes are assigned by the Global Standards Organization. If you need them for your products, here is all the information you need. 

EAN barcodes

EAN (European Article Number) codes are similar to UPC barcodes, but more common outside North America. They include an extra country code, so they’re widely used in global supply chains. Subcodes include EAN-8, EAN-13, EAN-14 and EAN-18.

The elements of EAN codes are:

1. Country code: The first 2-3 digits indicate the country of origin.
2. Manufacturer code: The next 4-5 digits identify the company.
3. Product code: These specify the item itself.
4. Check digit: This last digit ensures accurate scanning.

EAN-128 / GS1-128

GS1-128, previously known as EAN-128, is based on Code 128. Its elements are:

1. Application identifier (AI): A 2-4 digit prefix that tells you what type of data follows.
2. Data field: The actual data, which can vary in length based on the AI.
3. Check digit: Ensures the barcode scans correctly, though not always used.
4. FNC1: Function Code 1, a special character that indicates it's a GS1-128 barcode.

GS1-128 is like the Swiss Army knife of barcodes that can encode dates, batch numbers, quantities, and more. It's a workhorse in logistics and supply chain management.

There's also a subset of GS1 codes called ​​GS1 Databar, which is especially compact. It’s good for small items where space is limited. It’s commonly used in the healthcare and grocery sectors to display expiration dates and batch numbers.

GTIN

Global Trade Item Number (GTIN) is not a barcode type specifically, but rather a family of barcodes that includes both UPC and EAN barcodes. GTIN barcodes can be either 8, 12, 13, or 14 digits long, depending on the specific barcode type used. 

ITF-14

ITF-14, also known as Interleaved 2 of 5, is the go-to for cartons and pallets. It's a 14-digit barcode, and it's all about bulk. If you're shipping cases of your product, this is a likely choice of barcode.

What's inside an ITF-14:

1. Indicator digit: Tells you the packaging level (e.g., item, case, or pallet).
2. Company prefix: A unique identifier for your business.
3. Item reference: Identifies the specific product.
4. Check digit: Keeps the scanning accurate.

Codabar

Codabar is old-school but still kicking. It's often used in libraries, blood banks, and air parcels. It's simple and reliable for small amounts of data, and doesn't need a check digit (though you can add one).

What's encoded in Codabar:

1. Start/stop characters: A, B, C, or D to start and end the code.
2. Data characters: Numeric digits and some special characters like $ and /.

MSI 

MSI and Plessey are closely related number-only barcodes often used in inventory control and storage. Plessey is used mainly in libraries.

2D barcodes: The next level of data storage

Two-dimensional barcodes, also called matrix barcodes, are a step up from their 1D counterparts. Unlike linear barcodes, 2D barcodes can store significantly more data by utilizing a matrix or grid of squares, dots, or hexagons. This allows for the storage of alphanumeric characters, symbols, and even images. 

The ability to store larger amounts of data, and their compatibility with mobile device screens, makes 2D codes highly versatile. They can hold information such as product details, website URLs, or even entire business cards. Additionally, you can scan matrix barcodes from any direction. This makes them more flexible and easier to use.

QR codes

QR (short for Quick Response) codes, are the most well-known type of 2D barcode. If you’ve ever scanned a code on a restaurant table to see their menu, you know how useful they can be. 

QR codes contain:

1. Data cells: The small squares that make up the code.
2. Positioning markers: The larger squares that help smartphones or barcode readers to find the code.
3. Alignment patterns: Smaller squares that help align the code.

QR Codes are often used in marketing to link to websites or videos. They're also becoming increasingly popular for contactless payments.

Data Matrix

Data Matrix codes are commonly used in healthcare, pharmaceuticals and manufacturing. They're small and can store a lot of data, making them ideal for labeling small components.

They’re made up of:

1. Data region: The area containing the encoded information.
2. Finder pattern: The "L" shaped pattern that helps scanners locate the code.

PDF417

This is a format often seen on travel tickets and boarding passes. It contains:

1. Data columns: Vertical lines that store the data.
2. Start and stop patterns: These help the scanner identify the beginning and end of the code.

Aztec Codes

This is another code often found in the airline industry, especially for mobile boarding passes. Since it’s easy to display and scan from a phone screen, it’s also used a lot for event tickets. 

Aztec codes are compact and don't need a quiet zone (the blank area around a barcode). The anatomy of an Aztec code is:

1. Data cells: The concentric square rings that hold the data.
2. Finder pattern: The center bullseye that helps scanners locate the code.

MaxiCode

MaxiCode is another 2D matrix barcode often used for sorting and tracking packages. Each MaxiCode consists of:

1. Data region: Hexagonal dots that store the info.
2. Finder pattern: A bullseye in the middle for easy scanning.

Specialized Barcodes

ISBN and ISSN

The International Standard Book Number is a specialized encoding system used exclusively for books. It's a unique identifier that helps publishers, libraries, and bookstores manage their inventories. While technically not a barcode, the ISBN is often converted into a scannable format like EAN-13 to streamline the tracking process. 

ISSN (International Standard Serial Number) is used for newspapers, journals, magazines and periodicals. 

An ISBN is made up of:

1. Prefix: A 3-digit EAN prefix that indicates it's a book. Usually "978" or "979."
2. Group identifier: Specifies the language or country of origin.
3. Publisher code: Identifies the book's publisher.
4. Item number: Points to the specific book title.
5. Check digit: Ensures accurate scanning.

ISBN codes are crucial for the global book trade, making it easier to manage orders, listings, and inventories. They're usually found on the back cover or the copyright page of the book. If you're a small e-commerce business specializing in books, understanding ISBN codes is essential for efficient inventory management.

POSTNET

POSTNET is used by the US Postal service in mail sorting.  It contains:

1. Data characters: Numeric digits representing ZIP codes.
2. Check digit: To help ensure accurate scanning.

3D Barcodes

3D barcodes, also known as stacked barcodes, are a more sophisticated type of barcode that can store information in multiple layers. Unlike 1D and 2D barcodes, which are flat, 3D barcodes utilize multiple levels or layers of data storage. This allows for even greater data capacity and more complex information organization.

3D barcodes are particularly useful in applications where a large amount of data needs to be stored in a limited space. They are commonly used in industries such as health care and logistics, where comprehensive information, such as patient records or shipment details, needs to be encoded.

The majority of codes used in e-commerce retail are 1D or 2D barcodes.

Choosing The Right Barcode for Your Business

The type of barcode you choose can have significant implications for your business operations. It can affect:

Efficiency: Barcodes enable faster and more accurate data capture. Choosing the right barcode type can enhance the efficiency of inventory management, order fulfillment, and overall supply chain operations.

Data accuracy: Different barcode types offer varying levels of data accuracy. More advanced barcodes, such as 2D or 3D barcodes, can reduce the risk of errors and improve the accuracy of the information stored within them.

Here are some factors to consider when choosing barcode types for a business:

• Data needs: How much info do you need to store?
• Space: How much room do you have on the product for a barcode?
• Selling location: Are you selling locally or globally?
• Versatility: Some barcodes offer greater flexibility for different applications.

There are several companies that specialize in barcode software and printing barcode labels. Their websites are excellent resources if you want to know more:

• TEC-IT, based in Austria, offers both barcode creator software and label printing software. We used their free online barcode generator to create all the barcode samples in this article.
• Barcode-labels.com offers a custom label printing service and advice. 
• GS1 is the authority on UPC and EAN codes.