SKU
A SKU (Stock Keeping Unit) is an internal item code you assign yourself so a specific product or variant can be tracked in inventory and sales.
What is SKU?
SKU stands for Stock Keeping Unit and is an internal, alphanumeric code you assign to each product or variant so you can track it across inventory, sales, and reporting. Unlike a GTIN/barcode or an MPN, which are standardized manufacturer identifiers shared by every seller, a SKU is unique to your store. You choose the format yourself — e.g. TSHIRT-BLK-M — so the code stays human-readable.
Why does SKU matter?
A SKU is the key that ties your inventory, orders, and reports together. With consistent SKUs you can quickly see which exact variant is running low, what sells best, and what a warehouse pick refers to. Without them it gets hard to tell near-identical variants apart, and mistakes often reach the customer directly as wrong shipments or misleading stock levels.
Common use cases
- Stock counts and reordering — identify the exact variant fast without guessing.
- CSV import and export — SKU is often used as the key when updating prices or stock in CSV files.
- Product feeds — the SKU is typically mapped to the feed’s
idfield in channels like Google Shopping. - Integrations — ERP, accounting, and fulfillment systems match order lines on SKU.
Shopify perspective
In Shopify the SKU is set per variant — every product has at least one variant with its own SKU field under Inventory. Shopify does not require the field and does not enforce unique values, so two variants can accidentally share the same SKU. Set a fixed naming standard, keep the SKU identical across apps and inventory locations, and avoid reusing an old SKU for a new product.