What does 12M mean on skincare? Expiry dates made simple
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Simpler routines · 5 minute read
By HIGHBORN London editorial team · 23 September 2026
The open-jar symbol marked 12M means a cosmetic's period after opening is 12 months. The clock starts when you first open it for use, not when you buy it. Follow any best-before date and storage instructions too. If a product has changed or seems contaminated, stop using it even if that time has not passed.
There is probably something in your makeup bag that you bought for a wedding, opened for a weekend away, then forgot. There may also be three half-used moisturisers and a mascara whose age is now a mystery.
Before deciding what to keep, check the pack. Cosmetic dates are easy to confuse: some describe a product's durability, while others start a clock after opening. Neither is the same as a batch code.
Read these three things first
| Marking | What it tells you | What to do |
|---|---|---|
| An open jar with 6M, 12M or another number | The period after opening, in months | Record when you first open the product for use |
| “Best used before the end of”, or an hourglass with a date | The product's minimum-durability date | Follow the date and any storage instructions |
| A batch or lot code | A code that helps the maker identify the production batch | Keep it available if you need to ask about the product |
Under Government guidance for cosmetics sold in Great Britain, products with a minimum durability of 30 months or less carry a minimum-durability date. Longer-lasting products generally use a period-after-opening symbol, with exceptions where that indication is not relevant.
The batch code is not a universal expiry date. If the marking is unclear, ask the maker instead of guessing from an unofficial batch-code website. The Cosmetic, Toiletry and Perfumery Association's label guide also explains the open-jar symbol and why opening matters.
Make the date easy to remember
When you open something, add a small label: “Opened 23 September 2026.” Put it where it will not hide the ingredients, warnings or batch code. You can also make a note on your phone.
For a 12M product, that gives you a clear reference point in September 2027. It does not overrule an earlier best-before date, poor storage, damage or a change in the product.
You do not have to label everything in one evening. Start with what you open next. That small habit is more useful than trying to reconstruct the date of every purchase since your last holiday.
Sort your bag into three groups
Keep using: products that are within their stated life, stored as directed, unchanged and comfortable to use. Put your everyday items together so they are easy to find.
Check before using: unclear dates, unreadable labels or an opening date you cannot remember. Photograph the pack and contact the maker where useful. If you cannot establish that an old product is suitable to use, replace it rather than guessing—particularly around the eyes.
Remove from the routine: products past their stated life, visibly contaminated, or with an unexpected change in smell, colour or texture. Do not give a questionable product to someone else.
The UK Cosmetic, Toiletry and Perfumery Association (CTPA) advises checking both the labelled lifespan and any change in smell, colour or texture. A changed product may need replacing even within its stated life.
Give the tools a turn
Clean brushes belong in the clear-out too. CTPA recommends cleaning makeup tools regularly. Follow the tool maker’s care directions.
Use mild shampoo or brush cleaner, rinse thoroughly and lay brushes flat to dry. Follow the maker’s instructions for specialist tools and sponges.
Empty and clean the bag according to its care label, then let it dry fully before putting things back. A wipeable compartment can make the next clear-out easier.
What storage instructions add to the date
Dates assume you look after the product as directed. Keep lids secure, and choose a clean, dry place away from direct sun. Follow any specific temperature or storage instructions on the pack.
Before opening a second serum, ask whether you will use both within their stated life. A note of what is open can stop a forgotten bottle getting pushed to the back again.
For help organising what remains, our earlier makeup-bag decluttering guide covers the sorting job. Use this label guide alongside it when checking how long to keep an item.
A few common questions
Does 12M mean 12 months from purchase?
No. It refers to opening for use. Keep the receipt if useful, but record the opening date separately.
Can an unopened product last forever?
No. Check its date and storage directions. If there is no date and you have kept it for years, ask the brand for guidance.
Should every mascara or cream have the same lifespan?
No. Follow the particular pack rather than a generic timetable on social media. Ask the maker if its instructions are missing or unclear.
Sources and further reading
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