There is no one universal hiding place for a cosmetic batch code. Look at the product itself and at the original carton before deciding that a code is missing.
Inspect the base, sealed edge, label area, cap, and carton flaps for a short printed or stamped reference. Do not expect it to have a label saying “batch code” beside it. If the product is small, the useful identifying reference may be easier to find on the carton.
For cosmetics sold under EU rules, the batch number or identifying reference normally appears on both the container and packaging; small products can be an exception. Keep the carton until you have checked the product. Read Article 19 →
Lotly