SKU’s (Stock Keeping Units) are not Shopify specific.
A SKU is a unique identifier assigned to a product to help with stock inventory.
You can choose to use a SKU approach on your inventory or not.
For small shops (below 10 products), in my opinion a SKU is not needed but if you have a store with hundreds or thousands of products or more a SKU will certainly make your stock inventory much easier.
In a small store if you have products with long titles it is better to use a SKU to identify the items since it is much faster.
Moreover SKU codes can help you sell your products with Shopify much easier through other channels that integrate with Shopify or not.
What a SKU is not?
1. A UPC (universal product code) or barcode number, you know that number that you see below the barcode on products. SKU’s are mandatory to be different for each item in part but for UPC the code is the same.
2. A serial number to identify for the client his product ownership with product support or in any other specific cases.
Where SKUs are used?
SKU codes are used to keep track of products inventory in online stores, retail stores, warehouses, printed catalogs, online catalogs, fulfillment centers.
How does a SKU work?
SKU’s are stored in an internal tracking system software and specifically in the software database.
SKU’s are used for identifying products in your store quickly, tracking the location of items outside inventory, tracking the location of a product inside a warehouse.
Since SKU’s are unique identifiers for computers and ecommerce developers it is easier to work with them than with other data like product titles for example.
Scenarios where SKUs can be used in development is when you are presented with similar items from the same collection, on upsells and cross sells.
A SKU usually contains letters, numbers and dashes.
A SKU number can be simple for small stores with small inventories, but on complex inventories with thousands of products or more you’ll find more complex SKU’s.
SKU codes are human readable and you do not need a software (though a software can make it a lot easier) to read and understand the code.
How to create a SKU number the most correct and logical way?
My recommendation is to always start your SKU code with letters.
Never start your SKU code with a number and especially not with ‘0’(zero).
In fact, try to always avoid the number ‘0’(zero) in a SKU code since depending on the font used on your inventory software it can be confused with the ‘O’ letter. Same goes when the SKU code will be printed on paper in a catalog or brochure.
This will create confusion for your employees and for your customers too.
To avoid confusion even more in your SKU codes for simple stores with a couple of products you can separate the part with letters from the one with numbers through a dash.
Example: SKU-123.
In this way your employees will always know that on the left side of the dash will always be letters and on the right side will always be numbers.
Unfortunately this will not work in stores with big inventories since the SKU codes will be more complex and the dash needs to be used multiple times.
Try to keep it as short as possible and keep the format easy to understand.
Make sure that all letters and numbers in your SKU code have meaning. Also it is better that you have a table like the following one either in digital format or on a printed piece of paper so that your employees will get accustomed with the SKU codes:
| No. | Collection | Code | Sub collection | Code | Product number | Size | Code | Color | Code | SKU number |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Men | M | T-shirts | T | 001 | XS | XS | Red | 01 | MT-001-XS-01 |
| 2 | Men | M | Jacket | J | 002 | S | S | Blue | 02 | MJ-002-S-02 |
| 3 | Women | W | Boots | B | 003 | M | M | White | 03 | WB-003-M-03 |
| 4 | Women | w | Dress | D | 004 | L | L | Brown | 04 | WD-004-L-04 |
| 5 | Kids | K | Snicker | S | 005 | 35 | 35 | White | 05 | KS-005-35-03 |
Every column must be marked with a code only if it exists on the product.
How do I come up with the codes?
- I’ve taken from the collection name “Men” the first letter which is “M”.
- I’ve taken from the subcollection name “T-shirts” the first letter which is “T”.
- I’ve added a product number based on how many products I assume I’ll have in stock in the future. For this stock I imagined a couple of hundreds and this is why I’ve created a number with 3 characters and I’ll start the counting of products from “001”.
- The code for the sizes I’ll leave it as is since it is much easier to remember than a number. People are used with the sizes so it will be easier for them to give meaning to that part of the SKU code.
- For the colors you need to write all your product colors down and assign them a number. Why not use the first letter? Well many colors start with the same letter so it will start to get very confusing as you add more diverse colors. Assigning a number will be much easier to distinguish and memorize. It’s your call on how you want to proceed.
This is pretty much my system of assigning SKU numbers to my client products in the online store.
You can create your own system or follow mine.
Of course with more options you can add vendors, manufacturers, sales channels and many more. Your imagination is the limit.
Following these tips for creating a SKU number will save you a lot of headaches and lost time later as you increase your store inventory and customer base.
How a SKU code looks on a printed label?
The SKU code is marked with 1.
The UPC code is marked with 2.
The barcode is marked with 3.
As you see, a SKU code is different in composition than a UPC code. A SKU code can have as many characters as the product owner wants. On the other side a UPC code can only have 12 characters.
How to add a SKU to your products in Shopify?
Go to your admin dashboard and click on the “Products” menu item on the left side of the page:
On the “Products” page add a new product:
A new page will display. Scroll down until you see the “Inventory” section (marked with 1 in the image below):
Add your code inside the SKU (Stock Keeping Unit) input box (marked with 2 in the image above).
Once added your SKU code will look like this (marked with 1 in the image below) :
After you’ve added the code click the “Save” button (marked with 2 in the image above).
How to add a SKU to your product variants in Shopify?
On the same “Product details” page scroll down until you reach the “Variants” section (marked with 1 in the image below) :
Check the checkbox (marked with 2 in the image above) to display the fields to add the variants.
Click on the “Option 1” (marked with 1 in the image above) to open the drop-down menu (marked with 2 in the image above) and select the type of option that you need.
Add the option attribute in the box (marked with 1 in the image above). Once you type ↵ (Enter) or “,” (comma) a “Preview” section will display with the newly added variant and here you can add the SKU code for your variant (marked with 2 in the image above).
After you’ve added the code click on the “Save” button (marked with 3 in the image above).
You can edit the SKU code on variants from the “Variants section”. All you have to do is scroll/swipe left (marked with 1 in the image below):
Edit the code inside the SKU input box (marked with 2 in the image above).
Another option to edit the code is by clicking on the “Edit” button (marked with 3 in the image above). This will take you the “Edit variant” page:
Sales by product variant SKU in Shopify
Shopify has a sales report that can be filtered based on the SKU code. To access the “Reports” section go to “Analytics” menu item (marked with 1 in the image below) and click on the “Reports” menu item (marked with 2 in the image below) :
Once you see the page in the first section called “Sales” click on the “Show all” link (marked with 3 in the image above) to list all reports from that section. Click on the “Sales by product variant SKU” link like in the image below:
Sales by product variant SKU report should look like this:
My “Sales by product variant SKU” report is empty since my store is for demo purposes, only to help me write tutorials and there aren’t any actual sales on it.
Conclusion
I hope this tutorial helped you understand what a SKU code is, what is not and will help you to generate logical and easy to comprehend SKU codes.