Expiry date
The last date a product may be sold or used. Stock past this date must be pulled from sale and written off or returned to the supplier.
The expiry date is set by the manufacturer for the batch, not by you. Once it passes, the stock has no sale value and in regulated trades it must not be on the shelf at all.
The money side
Expired stock is cash you already spent. The loss is avoidable in almost every case, because you knew the date on the day you received the goods. What is usually missing is a reminder early enough to act — while the supplier will still take the goods back, or while a discount can still move them.
Work in windows, not on the day
Set yourself two lines. A near-expiry window where the stock goes on a watch list and gets pushed, discounted or returned, and the expiry itself where it is blocked from sale. For medicines many distributors accept returns only within a defined period before expiry, so the watch list has to start well ahead of that.
How KillStock handles it
Expiry dates are recorded per batch at goods receipt. Picking follows FEFO, so the nearest-expiry batch is offered first, and near-expiry stock shows up on the ageing and immobile-stock reports before it turns into a write-off.
A common mistake
Treating the oldest receipt as the nearest expiry. A supplier can and does send short-dated stock in a later consignment. Sort by expiry date, not by the day the box arrived.