Guide

How to find the expiration date from a lot or batch number

Can you find the expiration date from a lot number?

Not directly: a lot number tells you when and where a product was made, not when it expires. But it can lead you to the date in three ways:

1. 1

   Look right next to it. The date (EXP, Use by, or Best before) is usually printed beside or under the lot number.

2. 2

   Decode the production date. Many lot codes hide the manufacturing date. Add the product's shelf life to estimate when it expires.

3. 3

   Ask the manufacturer. Customer service can look up the exact expiry date for your lot number.

Use the SimSim app on a phone or a tablet. Use it alone or with your team—everyone sees the same up-to-date inventory. Get started for free—no credit card required.

Where to find the lot number on a package

Look for a short code that starts with LOT, L, BN, B/N, or Batch. It is usually stamped on the package, not part of the label design, and close to the expiry date:

• Cans and jars: on the bottom or the lid.
• Boxes and cartons: on a side flap or the bottom.
• Bottles: on the neck or the shoulder.
• Tubes: on the flat, sealed end.
• Medicines: on the end flap of the box and on each blister strip.

How to read the codes printed next to the lot number

Depending on the country, dates can be written DD/MM/YY, MM/DD/YY, or YYYY-MM-DD. If 03/04/25 could mean March 4 or April 3, check the manufacturer's website or ask the store.

How to decode the production date hidden in a lot code

Many manufacturers, especially of food and cosmetics, build the production date into the lot code. A common format is the Julian date: the year, followed by the day of the year.

Example: lot code L24123 → L = lot, 24 = 2024, 123 = day 123 of the year = May 2, 2024. If the product keeps for 12 months, it expires around May 2025.

Formats differ from brand to brand, so treat the result as an estimate. For medicines, baby formula, or anything you are unsure about, never rely on a decoded date: use the printed expiry date or ask the manufacturer or a pharmacist.

When to ask the manufacturer or a pharmacist

If the date is rubbed off or missing, or you can't decode the lot code, contact the manufacturer's customer service. Their phone number or website is usually on the package. Give them the product name and the full lot number: they keep records of every batch and can tell you when it was made and when it expires.

For medicines, check the box and the leaflet, or ask a pharmacist. Many medicine packs also carry a small square 2D code (Data Matrix) that stores the batch number and expiry date for pharmacy systems.

For businesses: keep the lot number with the expiry date

The same product can arrive in several batches with different expiry dates. If you only record the product name, you lose track of which batch expires first, and you can't answer quickly when a supplier asks about a specific lot.

• Record both on arrival: write down the lot number and the expiry date together when stock comes in.
• Keep batches separate: even for the same product.
• Follow FEFO: sell or use the batch that expires first.
• Search by lot: if a supplier or an authority asks about a batch, check your stock by lot number.

SimSim does this for you: take a photo of the label and the AI logs the expiry date and the lot number together. You can then search any product by name or lot number and get alerts before each batch expires. SimSim doesn't look up dates online; it records what is printed on your products.

Frequently asked questions