In wholesale an order rarely goes out in one piece. The customer wants 500; you have 300 in the warehouse, you ship those, and the remaining 200 follow when stock arrives.
At that point two separate questions appear, and most businesses try to track them with a single number:
- How much of this order do I still have to ship?
- How much of this order have I invoiced?
The two are independent. You can ship now and invoice at month end. You can invoice a prepaying customer before shipping. Try to hold both in one "remaining" column and sooner or later you will ship the same goods twice or invoice the same line twice.
Kumpara keeps the two numbers separately on every order line. For each item you see the quantity left to ship and the quantity left to invoice. A delivery note reduces only the first; an invoice reduces only the second. Go past either and the system stops you, so over-shipping and double invoicing do not happen by accident.
The practical payoff shows up at month end: five delivery notes issued to one customer across the month can be combined into a single invoice. The invoice lines come from the delivery notes rather than being retyped, and which invoice closed which notes is recorded.
It works in reverse too: if the customer drops the rest of the order you close it, and the remaining quantity leaves your open-work list.
The same discipline applies to stock: stock moves when the goods leave, not when the invoice is issued. Even if you invoice at month end, the warehouse figure tells the truth.