What is a SKU Number? Create, Manage & Track Inventory [2026 Guide]

A SKU number (Stock Keeping Unit) is a unique alphanumeric code that ecommerce sellers use to identify, track, and manage every product in their inventory. Unlike barcodes or UPCs assigned by manufacturers, SKUs are custom-created by your business — giving you full control over how products are organised across Shopee, Lazada, Amazon, Shopify, and your warehouse.