E-commerce and payments
What is SKU?
A SKU is the unique code identifying one sellable configuration of a product — not one product. A shirt in three sizes and four colours is one product and twelve SKUs, and confusing the two is where catalogue data models go wrong.
Also called: stock keeping unit
Why the distinction matters
Stock, price and sometimes weight attach to the SKU rather than the product. A data model that tracks stock at product level cannot answer whether the medium blue one is available, which is the only question the customer is asking.
Designing SKU codes
- Meaningful enough for a human to recognise in a warehouse
- Stable — never reuse a code for a different item
- Consistent in structure, so sorting and filtering work
- Unique across the whole catalogue, not per category
Where it shows up in SEO
Product schema accepts sku, and including it helps disambiguate identical-looking products. It also matters for merchant feeds, where a missing or unstable SKU causes items to be rejected or duplicated.
Where this is covered in depth
A definition can only go so far. E-commerce website development: what the whole build actually involves covers this properly — 7 minutes, free, no email required.
Who wrote this
Anas Bin Masud builds e-commerce sites and does technical SEO for businesses in the UK, Canada and Pakistan. These definitions come from client work rather than from a content brief — where an entry describes a mistake, it is usually one found on a real site. More about how I work.