Keep Them Short Another thing you should put in mind when trying to create an SKU number for a product is its length. You should make the code as short as possible. The reason for this is simple - most times, long SKUs make it very difficult for people to read and understand. And apart from that, it doesn't always work for all inventory management systems.
Avoid Spaces and Special Characters When creating an SKU number for a certain product, you must avoid using spaces and special characters. That's because they'll end up confusing people instead of making things easy for them as intended.
Avoid reusing SKUs The first thing that you need to know before creating your SKU numbers is that it isn't a good practice to reuse SKUs. As such, you must make each code unique to a specific product. Furthermore, it's worth knowing that there are cases when you can reuse SKUs. Although it's not advisable, you can reuse SKU numbers after a few years of originally creating them. However, this should be after several total catalog refreshes to identify that you've completely sold out all products using the SKU number.
Avoid starting the SKU with the number 0 Although starting the SKUs with numbers isn't a good practice, what's even worse is starting them with the number 0. Addressing the first issue, it's advisable to always start an SKU with letters. Doing that makes them stand out in spreadsheets, which are usually filled with numbers. Furthermore, as for the number "0", you need to avoid starting it because there are few data storing software out there that might interpret it as "nothing". For instance, when you have 024567, these systems might interpret it as 24567.