Every seller eventually needs a SKU generator, usually the week their spreadsheet hits 200 products and "blue t-shirt" could mean three different items. A SKU (Stock Keeping Unit) is simply a unique code per product and variant. Set up the system before you need it and you will never do the painful cleanup.
A SKU format that scales
Build each SKU from 3 to 4 meaningful segments: category code, product identifier, attribute, and sequence number. Example: TS-BLU-M-001 reads as T-Shirt, Blue, Medium, item 001. Keep each segment short (2 to 4 characters), use only letters and numbers, and avoid characters that confuse spreadsheets like slashes or leading zeros that Excel strips.
Rules for SKU sanity
- Unique forever: never reuse a SKU, even for discontinued items
- No meaning that changes: do not encode the price or supplier, those change
- Variants get their own SKU: each size and color combination is a distinct SKU
- Keep it readable: if you cannot read it over the phone, simplify it
Generate them in bulk instead of typing
Hand-typing hundreds of codes is where inconsistencies creep in. Our free SKU generator builds them for you: set your prefix, starting number, and how many you need, and it produces a clean batch you can copy straight into your inventory sheet. Consistent numbering from day one means no cleanup later.
SKUs vs barcodes vs UPCs
A common confusion: SKUs are your internal codes, while UPCs and barcodes are universal product identifiers required by marketplaces like Amazon. You assign SKUs freely; you buy or are assigned UPCs. Most sellers need both, and keeping them in adjacent spreadsheet columns saves endless headaches at listing time.