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Basmtak Books
Inventory and manufacturing

Costing method and negative stock

Choose how the cost of goods leaving is worked out, and whether the system lets you sell more than you hold or issue an expired lot.

4 min read 4 steps Open this screen in Books
This feature comes with certain plans. If it is not in your menu, it is not in your business's plan.

Open the stock settings

Open Settings from the side menu and scroll to the Inventory section. It has three choices. Press Save at the bottom of the page after any change.
Open the stock settings

How goods leaving are costed

This choice (1) sets the cost charged to a sale. If you bought 10 units at 100, then 10 at 120, and sold one:
  • Weighted average: it costs 110, the average of what you hold.
  • First in, first out (FIFO): it costs 100, from the oldest batch.
Weighted average is the starting setting.
A change applies only to future movements, and what already left is not re-priced. Decide on the method with your accountant before you start.

Issuing more than is on hand

This choice (2) sets what happens when more is asked for than is available, meaning on hand less what sales orders hold:
  • Allowed: the goods leave with a warning, the balance can go negative, and the last known cost is used.
  • Blocked: the document stops with a Not enough stock message until the goods arrive.
A negative balance means something was sold before its purchase was recorded, so its cost is a guess. Record the missing bill. The month-end review will flag Negative stock for you.

Issuing a lot past its expiry date

This choice (3) applies to items that track lots:
  • Allowed: expired lots are issued first so they do not linger.
  • Blocked: sales, deliveries and builds skip them, while write-offs, counts, transfers and supplier returns can still take them.
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