Serial and batch numbers: when you need them, and when a count is enough
Most stock only needs a count. Some needs tracking unit by unit or batch by batch, for warranties, recalls or expiry dates. How to tell which.
By The Osmuch team · · 5 min read
In short
- For interchangeable, low-value items, a count is enough.
- Track by serial number when each unit matters on its own: warranties, installs and valuable tools.
- Track by batch when products are made in runs and can expire or be recalled.
- With batches, use the one that expires first before newer stock.
- Tracking costs a little time on every movement, so use it where it pays for itself.
Every product needs a count. A few need more: a record of exactly which unit went where, or which batch it came from. Knowing which is which saves you from both extremes, tracking nothing and being caught out by a recall, or tracking everything and drowning in detail.
When a count is enough
For interchangeable items of modest value, such as fittings, fixings, cable and consumables, one screw is as good as another. What matters is how many you have. Tracking these individually would cost far more time than it could ever save.
When to use serial numbers
A serial number identifies one physical item. Track by serial number when it matters which unit a customer received: boilers, heat pumps, appliances and anything else with a manufacturer's warranty tied to the unit. It is also worth it for valuable tools and equipment, so you know which one is where. When a customer rings about a fault, you can find which unit you fitted, when, and on which job.
When to use batch numbers
A batch, or lot, number identifies a production run. Track by batch when products are made in runs and have expiry dates or might be recalled: sealants, adhesives, chemicals and similar. If a manufacturer recalls a batch, you can see at once whether you have any and where it went.
With expiring stock, the rule is to use the batch that expires first before newer stock, sometimes called first expired, first out. It stops good stock going out of date at the back of the shelf.
The cost of tracking
Tracking by serial or batch means recording the number every time stock comes in and goes out. That is a few seconds each time, and barcodes make it quicker, but it adds up. Start with the products where a warranty, a recall or an expiry date makes it worth it, and leave everything else as a simple count.
Questions
What is the difference between a serial number and a batch number?
A serial number identifies one individual item. A batch number identifies a production run of many items made together, usually sharing an expiry date.
Do I need to track every product by serial number?
No. Only products where it matters which individual unit went where, such as items with warranties or valuable equipment. Most stock only needs a count.
What does first expired, first out mean?
Using the batch with the earliest expiry date before newer stock, so products do not go out of date on the shelf.
Doing this in Osmuch
In Osmuch each product can be tracked by a simple count, by serial number or by batch. Serial-tracked units are recorded one by one, with whether each is in stock, allocated, sold or returned, and the project it went to. Batches carry their quantity and expiry date. Tracked products are always counted in whole units, while everything else can use part quantities.
Guide: barcodes batches and serials · Guide: adding your first product · Guide: low stock alerts and locations