Batch code generator: traceable codes and honest best before dates
Build a batch code that identifies the day, the formula and the run, then set a defensible best before or period after opening date from the shortest lived ingredient.
A batch code is the thread between a jar on a shelf and the day you made it. If a customer complains, or a supplier recalls a lot of shea, the code is what tells you which units are affected and which are not. It costs nothing to run a sensible scheme, and there is no way to reconstruct one after the fact.
Use a code that encodes the date, the formula and the run number, for example LIP01-260906-02. Print it on the container, write it in the batch record, and keep the record for at least the life of the product plus a year. A best before date comes from the shortest lived ingredient, not from the day you filled.
Build a code
The tool formats and dates a code. It does not decide your shelf life: that comes from your ingredients, your packaging and, if you sell, your stability evidence. The shelf life calculator estimates the limiting factor and shelf life testing explains what evidence actually supports a date.
What a code has to do
A batch code is not a serial number for its own sake. It has one job: given a unit in someone's hand, you can find the record of how it was made. Three fields do that reliably.
| Part | Example | What it recovers |
|---|---|---|
| Product and version | LIP01 | The exact formula, including the version you were making that month |
| Date | 260906 | The raw material lots open on that day, and the conditions |
| Run | 02 | Which of that day's batches, when you made more than one |
Anything that identifies those three things works. Julian dating (year plus day of year) is common because it is compact and hard to misread as a US or European date. What does not work is a code that only says the month, or one that changes format between batches, or one that lives on an outer carton the customer throws away.
The record behind the code
The printed code points at a record. For a small maker that record is a single page or spreadsheet row per batch, and it needs: the formula version and every ingredient with its supplier lot number, the weights actually used, the melt and pour temperatures, the yield and unit count, who made it, and anything unusual. Keep the raw material certificates alongside it. The batch scaling page shows the arithmetic that belongs in the same record.
Retention is the part people skip. Keep records for at least the product life plus one year, longer if you sell into the EU or UK, where a responsible person must hold the product information file for ten years after the last unit is placed on the market. If you sell in the United States, MoCRA record keeping for adverse event reports runs on its own clock, and selling balms in the UK and EU sets out the European side.
Setting a date you can defend
The shelf life of an anhydrous balm is the shelf life of its most fragile component, counted from the day that component was made, not the day you used it. An oil that arrived with nine months left does not get eighteen because you melted it into wax. That single point is behind most over-optimistic best before dates on small brand labels.
Record the supplier's expiry date for every oil as it arrives, and take the earliest one into the batch record. Your best before is that date, or your own tested figure if it is shorter.
In the EU and UK the rule of thumb is mechanical: a minimum durability under 30 months takes a best before date, and 30 months or more takes the open jar symbol with a period after opening instead. An anhydrous balm often qualifies for the symbol, but only if you can support the claim. In the United States there is no general requirement to date a cosmetic, which does not make an unsupportable date any safer to print.
Frequently asked questions
Is a batch code legally required on a balm?
In the EU and UK, yes: a cosmetic must carry a batch number or a means of identifying the batch. In the United States there is no general requirement for a cosmetic batch code, though MoCRA record keeping and any recall make one close to essential in practice.
What should the code actually contain?
Enough to find the record: which formula, which day, which run. Everything else is optional. Codes that encode the shift, the operator or the container size are fine as long as the format never changes between batches.
Where does the code go?
On the immediate container wherever possible, because outer cartons get thrown away. On a lip balm tube that usually means the base or the label; on a tin, the underside. Ink that survives handling and a little oil is worth testing before a big run.
How do I choose a best before date?
Start from the earliest expiring raw material, not the fill date, and shorten it if your own testing or packaging suggests you should. An oil with nine months left caps the product at nine months whatever the wax would tolerate.
When do I use the open jar symbol instead of a date?
In the EU and UK, when the minimum durability is 30 months or more. The symbol states how many months the product stays good after opening, which for an anhydrous balm in a tin is commonly 12 to 24 months, and it still has to be supportable.
How long do I keep batch records?
At least the shelf life plus a year for a hobby scale operation. If you sell in the EU or UK, the responsible person keeps the product information file for ten years after the last unit was placed on the market, and batch records are part of what sits behind it.
Sources and further reading
- European Parliament and Council, Regulation (EC) No 1223/2009 on cosmetic products, Articles 11 and 19.
- Office for Product Safety and Standards, Cosmetic products enforcement guidance, United Kingdom.
- US Food and Drug Administration, Modernization of Cosmetics Regulation Act of 2022: record keeping and adverse event reporting.
- International Organization for Standardization, ISO 22716 Cosmetics, good manufacturing practices, Geneva.
Reviewed and updated 6 September 2026. Spotted an error? Tell us and we will fix and log it.