What is the best barcode type for inventory?

For internal inventory, Code 128 is the best barcode type for most businesses: it encodes letters and numbers (so real SKUs work), it's compact, and every scanner reads it. Use it for shelf labels, bins and internal product labels.

The other types have specific jobs: UPC/EAN are for retail resale — if your products sell through stores or marketplaces, those numbers come from GS1, but they identify the product globally, not your internal stock. QR codes and DataMatrix hold much more data and scan brilliantly with phone cameras — good when you want a label to carry a URL or batch info, or when labels get printed small.

Practical setup most small businesses land on: Code 128 for internal SKUs, keep the manufacturer's UPC/EAN as a secondary identifier, QR only where phones are the scanner.