Demystifying Barcodes: Your Comprehensive Guide to ASIN, UPC, EAN, ISBN, SKU, and More.

Elise Jackson

Post details

  • AUTHOR: Elise Jackson
  • CATEGORY: Amazon Operations
  • DATE: 27/03/2024

What has black and white stripes and holds important information?

Answer: Barcodes. These little patterns hold information about products and are an important part of selling products, especially on Amazon.

But, do you know your ASIN, UPC and EAN from your ISBNs or SKUs? These are terms that we use every day on Amazon to identify products. In this article, we lift the lid on everything you need to know about Amazon barcodes and their crucial role.

What is a barcode?

We’re about to geek out on Barcodes but we’re here for it. Basically, a barcode is a method of presenting information that can be read by a machine, like a scanner. The lines and patterns represent data and once scanned the information shows up on the computer.

There are two types of barcodes: 1 Dimensional (1D) and 2 Dimensional (2D).

The barcodes you see on products with vertical lines and numbers at the bottom are 1D. They carry information about the product, country of origin etc.

QR codes that consist of squares, and dots – and are presented roughly as a square – to code data are known as 2D barcodes which present more detailed information about the product that can include images.


What are the types of barcodes you will find on Amazon?

Now that we have covered what barcodes are, let’s take a look at the terms you will come across on Amazon:

1. ASIN: Amazon Standard Identification Number
2. UPC: Universal Product Code
3. EAN: European Article Number
4. ISBN: International Standard Book Number
5. SKU: Stock Keeping Unit
6. FNSKU: Fulfilment Network Stock Keeping Unit


ASIN: Amazon Standard Identification Number

Your Amazon Standard Identification Number (ASIN) is a unique identifier of 10 letters and/or numbers for an Amazon product.

An ASIN is created when you add an item to your catalogue on Amazon and is a barcode that is only used on Amazon. It’s used to identify products on the site, reference products, track inventory, and index catalogues


How do you find your ASIN number?

You can find the ASIN number in two places. One place is on Amazon’s product detail page in the ‘product detail section’

And the other you can get from the web address.

Note: There are rules about variations of products where there is one parent ASIN and then variations of the product, and how to list them. You can read everything about how to list ASINs in Amazon’s guide.


UPC: Universal Product Code

A Universal Product Code is a product identifier on packages that consists of 12 unique digits, and a series of vertical black lines that are read by barcode scanners. UPC barcodes are heavily used in the USA and Canada.

It consists of a UPC company prefix, an item reference number and a check digit at the end.

Once scanned at checkout, it shares information about the product features, and the brand name etc.

To obtain your UPC number your product – if you are selling to the USA and Canada you need an UPC! – you need to first work with the Global Standard Organisation. Apply to become part of their system to get your company prefix number, then use a UPC generator to get the rest of your barcode.


EAN: European Article Numbers

The European Article Number (EAN) is the product identifier that is used in the rest of the world, and features 13 numbers instead of 12 like UPC, and consists of black and white stripes.

Most modern barcodes can scan both UPC and EAN codes, but it makes sense to opt for EAN codes if you plan on selling products internationally.

To obtain your EAN number, you can buy it from barcode sellers, or if you have a barcode number and need to generate a barcode image you can use free barcode generator tools.


ISBNs: International Standard Book Numbers

Text-based products like books, magazines, e-books etc use an International Standard Book Number (ISBN) barcode which carries information about the book registrar, edition, format, title etc in 13 digits and black and white lines.

You can obtain the ISBN through a local ISBN agency, or platforms like Amazon’s Kindle Direct Publishing.


SKUs: Stock Keeping Units

An SKU (Stock Keeping Unit) code on Amazon is a unique identifier assigned to each product in a seller’s inventory. It helps in managing inventory, tracking sales, and organising products effectively. SKU codes are typically alphanumeric and can be customised by the seller to suit their inventory management system. This is especially handy when you have variations of products and want to differentiate between products.

During the product listing process, you’ll be prompted to assign an SKU to your product. You can either use a system-generated SKU or create your own custom SKU based on your inventory management needs.

Once your product is listed, you can manage its inventory using the SKU assigned to it. This includes tracking sales, restocking inventory, and making adjustments as needed.


FNSKU: Fulfilment Network Stock Keeping Unit

Also known as the ‘Amazon Barcode’, the Fulfilment Network Stock Keeping Unit (FNSKU) barcode is what Fulfilment by Amazon (FBA) sellers use that identify your products and connect products to your Amazon Seller account.

Amazon likes to use the FNSKU over UPC or EAN as it’s easier to track and manage inventory. The FNSKU tells Amazon what the product is and whom it belongs to – so information about the seller (don’t confuse them with ASINs which only give information about the product!)

You can set your barcode preference via Seller Central to choose to use FNSKU or UPC/ EAN.

To set up your FNSKU just go to ‘manage inventory’ on Seller Central and ensure the FNSKU column is checked in your preferences.


Difference between SKU and FNSKU

While they are both connected, there is one main difference between the two barcodes – FNSKU is used for processing the entire shipping process, whereas SKU is for tracking the product for inventory and sale purposes and is only used by sellers and Amazon.


Our thoughts

While this may not be on top of the list of exciting topics to think about on your seller journey, barcodes are incredibly useful and important to get right to ensure the seamless transportation and management of your products!

The Amazon-specific barcodes like ASIN, SKU and FNSKUs can be generated directly by Amazon, whereas UPCs, ISBNs and EANs are generated with Amazon. We recommend reading the rules of where you are based to see what barcodes are relevant for you to use.

Still unsure about which barcodes you need to get for Amazon? Don’t worry, our team of Amazon experts is here to answer any queries for you – big or small! So, don’t hesitate to ask by booking a call or sending us a message.

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