No, meals can auto-generate one. A meal's Barcode field (on the Meal edit page, which only shows up when the POS module is enabled) can be filled automatically in one of two formats controlled by Client Config > Business: Cart > "Meal Barcode Format": UPC-A (12-digit retail) — a 5-digit prefix ("UPC-A Barcode Prefix", default 20000) + a 6-digit padded meal ID + a computed check digit, guaranteed unique — or Code 128 (alphanumeric) — MEAL-000123 style. The Barcode field's placeholder reads "Auto-generated or enter manually", so you can also type/paste a barcode into it yourself instead.