What is a SKU? Meaning, examples and how to create them

A SKU, short for stock keeping unit, is a code you assign to each distinct product you sell so you can count, order and find it. If you sell a T-shirt in three sizes and four colours, that is one product but twelve SKUs, because each combination is counted and reordered separately.

Key takeaways

• One SKU equals one sellable variant: size, colour, pack size or any attribute you track separately.
• A SKU is your own code. A barcode (GTIN, UPC or EAN) is a global one. Keep a mapping between them.
• Short, consistent, human-readable codes prevent picking and ordering mistakes.

SKU versus barcode versus product ID

A SKU is internal and meaningful to you. A barcode is a standard number printed on the pack that scanners read, and it is the same everywhere the product is sold. A product or variant ID is a number your platform assigns, such as Shopify's. You need to keep all three linked to the same item, so scanning a barcode finds the SKU and an order line finds the stock.

A simple structure that works

A good SKU is built from a few parts in a fixed order, for example:

TEE-CREW-BLK-M
category - style - colour - size

Rules that save pain later:

• Use capital letters and digits, with hyphens as separators.
• Avoid characters that spreadsheets and scanners mangle: spaces, slashes, and a leading zero that Excel will drop.
• Do not reuse a SKU for a different product, even after you discontinue the original. Old orders refer to it.
• Keep it short enough to read aloud and write on a carton.
• Do not encode things that change, such as a supplier or a price.

Why SKUs matter for planning

Forecasts, reorder points and safety stock are all calculated per SKU. If two variants share a SKU you cannot tell which one is running out. If one product is split across several SKUs by accident, each looks slow and the demand picture is fragmented. Clean SKUs are the base for every number that follows, from days of cover to ABC analysis.

Bundles and kits need care. A bundle can have its own SKU for selling, while its components keep theirs for counting, so a bundle sale reduces component stock. See bundles and kits inventory.

Common mistakes

• Different SKUs for the same item across sales channels, so stock is split.
• Reusing SKUs after a product is discontinued.
• Blank SKUs on Shopify variants, which makes matching to suppliers and warehouses unreliable.
• Putting meaning that changes, like a season, into the code.

How Stokrio uses SKUs

Stokrio keeps a product catalogue by SKU, synced from Shopify, and runs its forecasts and reorder suggestions at that level. Fixing duplicate or blank SKUs before you connect any planning tool saves a lot of cleanup.