How to read a La Mer batch code
La Mer belongs to the Estée Lauder Companies group, which prints a short 3-character code, usually on the bottom of the product or the box:
- 1st character: the factory (plant) code
- 2nd character: the month (1–9 = Jan–Sep, A = Oct, B = Nov, C = Dec)
- 3rd character: the last digit of the manufacturing year
For example, A73 decodes as shown when you enter it above. Because only one year digit is stored, a product made ten years earlier shares the same code. That is why we show both possibilities.
Frequently asked questions
How do I read a La Mer batch code?
La Mer (Estée Lauder Companies) uses a 3-character code such as "A73". The first character is the plant, the second is the month (1–9, then A = October, B = November, C = December) and the third is the last digit of the year.
Where is the batch code on cosmetics?
Usually it is a short code stamped or embossed on the bottom of the product or printed on the crimp of a tube, often near the barcode on the outer box. It is different from the barcode.
What does the open-jar symbol (e.g. 12M) mean?
That is the PAO, or Period After Opening. It is the number of months a product stays good once opened, regardless of when it was made.
Do cosmetics really expire?
Yes. Preservatives weaken over time and actives such as vitamin C, retinol and sunscreen filters lose strength. Expired products can irritate skin, harbour bacteria (especially mascara) or simply stop working.
Does a valid batch code mean a product is genuine?
No. A batch code only tells you when a product was manufactured, based on the brand's own coding convention. It does not confirm the product is authentic, registered for import, or free of counterfeit stock. During sale season especially, also check the seller's ratings and look for manufacturer or importer details on the pack.
Batch-code formats are based on publicly documented manufacturer conventions and can change. If in doubt, contact the brand with your code. Shelf-life figures are industry averages.
New to batch codes? How to read batch codes and PAO symbols explains what each marking means and how long products last once opened.
Not sure a product is genuine? Our step-by-step guide to checking a cosmetic is original covers sellers, labels and what to do if you've been sold a fake.
Buying during a sale? A batch code confirms when a product was made, not whether it is genuine or legally registered for import. See our guide on checking a cosmetic's registration before you buy.