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From listing requirements to packing compliances and shipping prerequisites, you have to take care of a lot of things at once. With so many things already on the plate, some details can get confusing.

Case in point: all the product identifiers you come across while selling on Amazon, including SKUs. 

If you wonder why there is the need for SKU amid all the other product identifiers, keep reading. 

This post will try to clear this confusion for you. Here, we'll discuss and dissect what seller SKU is on Amazon and how you should go about them. 

Without any further delay, let’s start our discussion.

What Is Seller SKU and Why Do You Need It?

In general, Stock Keeping Unit (SKU) is an alphanumeric product identifier. You can see it as a scannable barcode on retail products. As the full form of this acronym suggests, SKU helps in keeping track of inventory. 

At Amazon, the meaning of SKU slightly changes. It specifically becomes a merchant’s product identifier. Amazon asks sellers to assign an SKU to all their products and variations and put them in the vital information section of corresponding listings. 

Amazon utilizes these merchant-assigned product identifiers to associate items mentioned in the inventory file to relevant product detail pages in its catalog. SKUs just appear on the Seller Central of the seller they belong to. It is not mentioned on the product page and thus not visible to other sellers and customers. 

Anatomy of an SKU

Seller SKU can be a string of alphanumeric characters. You can separate the characters by hyphens (dashes) to represent different product details. The length of an SKU should not be more than 40 characters, including the hyphens. 

Moreover, Amazon hasn’t standardized a particular format or template to create SKUs. It is sellers’ discretion to create SKUs in whichever format they deem suitable. An SKU can be as brief as AA-001 to as lengthy and ABC-001-R-M-0921-N. The length of the SKU depends on how much information (product details and attributes) you want to wrap in it.

Why Do You Need a Seller SKU on Amazon?

It is imperative to understand the wide-ranging purpose of seller SKU before you know how to create them. 

Helps You with Easy Identification and Representation of Your Products

With the help of an SKU, you can enclose a long description of your product into a string of numbers and alphabets. These shorthand identifiers come in quite handy when your inventory consists of multiple products with various variations. It is convenient to represent a product with a short, single code instead of long product titles. 

For instance, HNB-DS50W is an easy way to identify and represent a Home N Bliss White Door Draft Stopper 50mm Wide product.

Data Management Becomes Easy

The use of SKU across all the spreadsheets will keep your data tidy and easy to read. Also, if you are using an inventory management system to streamline your supply chain, you will find SKUs a godsend. Those software applications are developed to perform better with shorter, code-like inputs. Using the example mentioned above, it will be easier for you to use codes such as HNB-DS50W in your inventory management system rather than full product title. 

Improves Communication with Vendors

SKUs also make it easy for you to communicate with vendors and suppliers. If you have worked out the SKUs of your products along with vendors, you can have your correspondences short and easy. You won’t have to mention the complete product name with all its attributes in every email, message, and invoice. You can use SKU instead and keep your communications concise and time-efficient.

Amazon Needs It to Match Your Items with Corresponding Product Detail Pages

There is a reason why seller SKU is not just an option but an obligation. Amazon uses them to tie your product with relevant product detail pages on its catalog. Therefore, even if you don’t assign an SKU to any of your listed items, Amazon gives it an arbitrary SKU to have that product-product detail match.

It is a simple illustration of how SKU ties a product to its relevant detail page from Amazon's catalog.

Amazon Seller SKU Rules

These are the essential Amazon seller SKU rules you should know.

  • Every item mentioned in your inventory file must have a unique SKU e.g. Bloom’s red and blue socks for adults will have different SKUs. 
  • You can’t simply change the existing SKU just by changing it in the inventory file. If you have to change the SKU of a product, you will have to delete its listing and then list it again with the revised inventory file.
  • The new data for existing SKUs in a recently uploaded inventory file will automatically overwrite and replace data of the same SKUs from previous feeds.

How to Create Seller SKU on Amazon

Creating seller SKUs on Amazon is as easy as it gets. You don’t need any specific application or software to create SKUs. Nor do any expert knowledge is required to craft these seller-oriented product identifiers. If you have enough information about the given product and a notepad, you can create SKUs.

As mentioned earlier, there is no particular format to follow when it comes to SKU creation. As long as your SKU remains below 40 characters, you can opt for any format you think is easy to remember and use.

Therefore, we are not advocating any particular SKU format here. Instead, we will give you a broader view of how you can create your own SKUs that can help you streamline your product and inventory management.

Ingredients of an SKU

These are some of the information pieces you may want to encapsulate in your SKUs.

  • Product name: The general product title e.g. shirt, vacuum cleaner, cell phone cover.
  • Product category: The broader category an item is falling into: For instance, shirts, socks, and bibs can all be categorized as clothing/apparel. 
  • Product condition: The physical condition of the product i.e. new, used, or open box.
  • Cataloging/inventory inclusion date: The time when you have made that particular item part of your Amazon inventory.
  • Product supplier/source: The vendor or brand you have sourced the product from.
  • Attributes and features: Size, color, material, and other standout features of the item.
  • Seasonality: The seasonal appeal of a product where it is sold better during a particular duration e.g. summers, winters, holidays.
  • Cost: The price at which you have sourced the product. 
  • Batch Number, Sequence: The sequential number of the products in which they are added to the inventory.

You can use different alphanumeric combinations/identifiers to denote these bits of information. Moreover, you are not bound to use only these product details. If your product has any attribute you consider essential for your inventory management, cost analysis, etc, you can include it in the SKU.

Creating a Custom SKU— A Step-by-Step Guide

As mentioned earlier, you can have as much customization as you want while creating SKUs. Here, we will share one of the many approaches you can use to create an SKU.

Start with the Supplier

Start the SKUs of a product by mentioning the supplier/source by assigning two or three-character codes to them. For instance, if you are sourcing products from Alibaba or Thomasnet, you can use AB or TN, respectively. 

The benefit of mentioning supplier/source at the start of the SKU is that you don’t have to look at your invoices to find out which product has been sourced from which supplier. The list of SKUs will tell you that.

Mention the Product and Product Category

If you are selling across multiple product categories, you may want to use a category identifier to keep things easy on the Seller Central and elsewhere. For example, if you deal in formal and casual apparel, you can differentiate it with identifiers such as FW (Formal Wear) and CW (Casual Wear). For shirts, pants, trousers, ties listed from that category, you can again use a double-character identifier e.g. SH for shirts, PT for paints, TR for trousers, TI for ties, etc.

Insert the Attributes and Condition

Mention the color, size, material, and condition of the product. You can use two letters to indicate colors, one letter for size, one for the condition, and two letters for the material.

RD-M-N-LT will be a red medium-sized new leather product.

State the Price

Many sellers don’t mention the cost of the product in their SKUs. We think stating the price there can help you instantly find out your profit margins and whether you should provide a discount on a product sitting on the shelf for long. You can use 3-4 characters to state the price e.g. 15D to say 15 dollars.

Suppose you come across an SKU created by the method we’ve just discussed.


It is a 18-character SKU and seems to contain a lot of information. Let’s unpack all that information while using the approach and sequence discussed above.

The given SKU suggests that the product is sourced from Alibaba. It is a shirt for casual wear. Moreover, it is a new medium-sized green piece that cost the seller seven dollars.

You can see that an SKU lets you contract product descriptions of several hundred characters to a 18-character alphanumeric string. If you think you don’t need such a long SKU, you can shorten it as per your requirements. Let’s look at some of the variations of this SKU.

  • CW-GR-M: A casual wear medium-sized green shirt.
  • SH-GR-M-7D: A $7 medium-size green shirt.
  • AB-SH: A shirt sourced from Alibaba.

4 Things to Remember While Creating Product SKUs

  1. Standardize a single SKU format across your venture for all the products and categories. Devise an SKU creation manual to ensure the entire team remains on the same page.
  2. Avoid starting SKUs with zero. It can create issues when used in data and management software.
  3. Use the same SKU for a similar product variation across different Amazon marketplaces.
  4. Keep your SKU units to alphabets and numbers. Avoid using symbols.
  5. Don’t create SKUs with dates and other variables. Such SKUs can get outdated with the arrival of a new batch. You will have to not just create new SKUs but also new listings of the same, existing listing.

Seller SKU on Amazon: FAQs

Before concluding, let’s answer some of the frequently asked questions around Amazon seller SKUs.

Is an SKU the same as a barcode on Products?

No, SKU is not the same as the barcode. The barcode you get from the Seller Central and affix on relevant products contains FNSKU and ASIN. Or, you get barcodes (UPC, EAN) from GS1. On the other hand, SKU is primarily a code for internal correspondence and coordination that you submit to Amazon and is mentioned in product entries on the inventory management tab.

Can you Change the Amazon Seller SKU for a Product?

No, you can’t change an existing seller SKU. You will need to delete the listing and create it again if you want to change its SKU.

Do I need an SKU to sell on Amazon?

Yes, SKU is an obligation to sell on Amazon. If you don't assign an SKU to your product, Amazon will do it at random.

Should I let Amazon create my Seller SKUs?

As mentioned multiple times, Amazon randomly generates and assigns SKUs. Those SKUs will be of use to Amazon only. You won’t be able to use those Amazon-generated SKUs for all the intents and purposes discussed in this article. 

What Is the Difference between ASIN and SKU?

Amazon Standard Identification Number (ASIN) is a unique code generated by Amazon to identify products listed on its different marketplaces. One ASIN (product) can have multiple SKUs (product variations). Moreover, ASIN is visible to everyone on the listing page, unlike SKU.

What Is the Difference between SKU and FNSKU?

Fulfillment Network Stock Keeping Unit (FNSKU) is a barcode generated by Amazon to track inventory through its fulfillment chain. It doesn’t have an alphanumeric structure of an SKU. Nor is it a barcode equivalent of the relevant SKU.

What Is the Difference between SKU and UPC?

Universal Product Codes (UPCs) are usually barcodes that global standard organizations assign to retail products. Thus, for a single product, they universally remain the same. In contrast, SKU is a custom alphanumeric code primarily generated for internal inventory management.

Final Words

A good SKU regimen will streamline your inventory management. For example, it will become easier to scan through products on the Seller Central with well-thought-out SKUs. Similarly, using data and management software and applications becomes easier when you use SKUs instead of product names and titles.

Whether you’re just starting your Amazon journey or been in the game for a while, ZonGuru has just what you need to improve your business. Sign up for a FREE trial today, cancel any time.

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