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GMP - Lot Numbers

Good Manufacturing Practices

Tracking and assigning lot numbers to your incoming ingredients and materials can help keep your products safe and also provide a way to debug it when things go strangely wrong.

Writing Lot Numbers

A “lot number” is a unique identifying number (or set of letters and numbers) assigned to one ingredient or material, that is assigned when the shipment is received. Lot numbers are required (by regulations) to track ingredients and materials in food, drugs, and nutritional/dietary supplements. They are not required for cosmetic ingredients, but they are included in all cosmetic good manufacturing practice guidelines and certainly are a good idea and smart thing to do.

Why are Lot Numbers Important?

Saved by the Lot Numbers!
We received a notice from our supplier that one of their lots of herbs had been contaminated by bugs. Luckily, we had written down the supplier’s lot number in our record, so we were able to determine that the herbs we received were NOT the ones that had been contaminated. If we hadn’t been able to confidently confirm our herbs were bug-free, we would have had to throw out our whole supply - at great financial loss.

When you assign a Lot Number to an incoming ingredient (provided you document the information about the ingredient when you receive it and you record its use in your Batch Record) you can easily track your use of that ingredient.

For example, if you had a two batches of soap turn out bad, you could determine if there was a common ingredient that could have caused the problem.

Another example, if you received a report from a customer that the lotion they purchased from you went bad (heaven forbid!), by going to the Batch Report for that batch of lotion, you could check all of the ingredient to see if there were any issues. In the event that one ingredient did have an issue, you would be able to go back to your Batch Records and see which other batch(es) had used that ingredient.

Assigning Lot Numbers

There are no specific rules on how Lot Numbers should be created or assigned - just that there is a unique identifier assigned to each incoming lot. In my experience, having a date embedded into the lot number helps with immediate recognition; you can instantly tell how old the ingredient is, even without checking your records. Something as simple as the date and number of the lot for that day would work:


You could also embed additional information into the lot number making it easier to tell at first glance who the supplier was along with the date received.


Remember, you are the only person who really needs to understand the code. So make up something that works for you and the way you think about and organize your products.

Keeping Track

The simplest and easiest way to keep track of your lot numbers is with a log. My lot batch numbers were recorded in a plain old composition book, purchased for 88¢ during a “Back to School” sale. I just wrote down the assigned lot number, when it was received, who it was from, whether it was acceptable or not, and any notes:


In addition to the columns shown above, you could also add in the supplier’s lot number (if provided), the quantity received, expiration date and/or the price paid.

If you are trying to go paperless, you could keep the same information in a spreadsheet or even a word processing document. Electronic files do have the added steps of having to get to your computer, open the file and enter the data. You also need to make sure that you have a back-up system in place.

Complete Information

Once you get your simple log into place, the next step is to set up a form on which you can record complete information about the incoming ingredient. If you have a form, then the log itself may require less data. The form should include everything that is shown above in the example log, plus the additional items noted.

Along with that information, you should also include details about how you verified the correctness of the item (was it what you ordered?) and that it met the specifications that you expected by visual inspection, feel smell, and/or testing. For a complete record, you should also attach the supplier’s quality analysis statement and any Safety Data Sheets provided by the supplier.

All that information should be kept securely and in a manner that makes it accessible when you need it. Scan the details and store in a suitable filing system on your computer or just keep a binder with the paper pages.

Well Stored Products

Labeling the Product

Finally, each ingredient should be placed in an appropriate container for storage. Oils and butters usually come in suitable containers, but items like herbs or color additives may need to be placed in air-tight jars or some kind. Make sure that each container is clearly labeled with the Lot Number, what it is, and the expiration date. Don’t mix lots - if you have two lots of the same ingredient, put them in separate containers so you can use the oldest one first.

Marie Gale is the author of Good Manufacturing Practices for Soap and Cosmetic Handcrafters, which is available in the HSCG Store.

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