How to read a coded expiration date?

Skincare packaging often uses a batch code instead of a printed expiration date, especially when total shelf life is over thirty months. The code is typically three to ten characters, stamped or dot-matrix printed on the bottom of a bottle, the side of a jar, or the crimp of a tube. To decode it, plug the brand name and code into a free online cosmetic batch code checker, which returns the manufacturing date and estimated shelf life. Pair that with the PAO symbol, the open-jar icon with a number like 6M, 12M, or 24M, which tells you how many months the product stays good after opening. Whichever date hits first is your stop date.