Cosmetic Batch Code FAQ
Short answers to the questions we hear most.
What is a cosmetic batch code?
A short code that identifies one production run. Some codes contain a manufacture month and year, others do not. See our guide to batch codes.
Is a batch code the same as an expiry date?
No. Follow the printed expiry date or the open-jar (PAO) symbol. A decoded manufacture date only helps estimate age.
Why can’t you decode my brand?
Because we have not found a documented format for it. We would rather say so than guess. Our methodology explains how we decide.
How accurate are your dates?
They are estimates with limited evidence, based on third-party sources, not on the brands. Month precision at best, and one-digit years can mean two different decades.
Can I use this to check if a product is fake?
No. A batch code cannot prove authenticity.
What is the PAO symbol?
An open jar with a number and M, such as 12M, meaning the product stays good for that many months after you open it.
What shelf life do you assume for unopened products?
A general 30-month guideline, shown separately and labelled as an assumption. You can change it in the expiry calculator.
Where is the batch code on my product?
Usually the base of bottles, the crimp of tubes, the underside of jars or the outer box. See the location guide with illustrations.
Is my data stored?
No. The codes and dates you enter are processed in your browser and are not sent to our servers.
Does this work offline?
Yes. Visit once, then the checker and calculators keep working without a connection. You can also add the site to your home screen.
How can I help?
Send a photo showing a batch code together with a printed manufacture date. Verified examples are how rules get added.
Do you earn money from this site?
Yes, through advertising and Amazon affiliate links. This never changes what a rule says. See the disclosures.