A lot number, or batch number, identifies a quantity of goods produced, processed or packed under practically the same conditions. It should be printed or stencilled clearly on every bag, and it must match the lab report, certificate of analysis and packing list for that lot.
Without a lot number, a test result cannot be tied to any goods, and a claim or recall cannot be limited to the affected bags.
What a lot should be
A lot should come from one production run or one homogeneous blend. If a plant puts goods from several runs under one number, a sample may not represent the whole lot. Agree in your spec how big a lot can be and what counts as one lot. Sampling then follows the lot.
What to mark on each bag
- Lot or batch number.
- Product name and grade.
- Net weight, and gross weight if your buyer asks.
- Date of production or packing, and best before date if needed.
- Origin: "Product of India".
- Bag number within the lot, if you want counts by lot.
- Your shipping marks or brand, if agreed.
- Organic or other certification references where they apply.
How it should be marked
- Printed on the bag or a sewn-in label, not on a loose tag that can fall off.
- Ink that does not rub off or run when damp.
- The same format on every bag and every document.
- Placed where it can be read when bags are stacked.
- Food-safe ink where it touches inner liners.
Lot numbers at loading and in claims
At loading, the inspector should confirm that bag markings match the packing list and the lab report. Mixed lot numbers in one container are fine if the packing list shows how many bags of each. A lot number on the report that appears nowhere on the bags is a serious warning. See what an inspector checks during loading supervision and what a packing list should show.
For prepacked consumer foods, EU law also requires a mark identifying the lot. For bulk ingredients, lot marking is mainly a contract and good practice requirement. Check the rules for your own packs.
When a problem is found, the lot number decides what is affected. If each lot is small and clearly marked, a failed test affects only those bags. If one number covers a whole container of mixed runs, the entire container may be held. Smaller, well-defined lots cost a little more in testing but limit your losses when something goes wrong. They also make a recall far easier for your customers to manage.
How Creston & Co handles this
We set lot size and bag marking in the spec, draw the sample from the marked lot and seal it. At loading we photograph the markings and check them against the packing list. Start with a free sourcing review.