Ask a distributor how they price and you will not hear a percentage. You will hear a scheme. Ten and one free. Fifty and six. A slab that changes at a hundred. It is the language the whole trade runs on, and almost no billing software speaks it.
What people do instead
They fold it into the rate. Eleven units go out, the bill shows eleven units at a rate low enough to make the total come out right, and the scheme disappears.
That works until somebody needs to know something. The retailer cannot see what they were given. Your own stock is right but your margin per item is now nonsense, because a discount that was really about quantity has been smeared across the price. And next month, when the scheme ends, nobody can tell which bills had it and which did not.
The free goods are a line, not a discount
Printing them as their own line on the invoice fixes all three. The retailer sees what they got. The rate stays the rate. And the bill is a record of the scheme rather than a record of the arithmetic somebody did in their head.
Two shapes, and they are not the same
A scheme either gives goods or gives a percentage, and confusing them is where the money goes.
- Free quantity — buy a certain number, get extra units at no charge. The value moves in stock, not in money.
- Slab discount — reach a quantity, get a percentage off that line. The value moves in money, not in stock.
The first affects what you have to send. The second affects what you get paid. A system that treats them as one thing will get one of them wrong.
Free goods repeat — and this is where it goes wrong
At buy ten get one, twenty-five units does not earn one free unit. It earns two, because the scheme applies twice over. Quietly capping it at one is an undercharge in the retailer's favour that the distributor only finds at month end, across every bill, all at once.
The leftover five earn nothing. The remainder is dropped rather than pro-rated, because half a free unit does not exist and nobody has ever shipped one.
The slab boundary nobody checks
When a scheme has several slabs, the one that applies is the highest whose minimum the quantity actually reaches. Below the lowest slab, nothing applies at all — which is correct, and is also the case people forget when they check a bill and expect to see something.
How this works in BizGST Pro
Schemes are set up per item, with slabs — a minimum quantity, and either the free units or the percentage that it earns. A scheme can also be left without an item, in which case it applies generally.
When both exist, the item's own scheme wins over the general one. That is deliberate: if you have a broad slab for large orders and also a specific arrangement for one fast-moving line, the specific arrangement is the one you meant.
Schemes carry dates, and both ends are inclusive — a scheme that runs to the end of the month still applies on the last day, which is the day it is being pushed hardest. Leave a date blank and that end is open.
Where it stops
This is quantity pricing, and only that. A discount on the whole bill at the counter is a different mechanism and lives elsewhere in the product; do not expect one to see the other.
It also does not decide anything for you. Whether ten-and-one is a good idea for your margin is a question the scheme engine has no opinion about. All it guarantees is that once you have decided, every bill says the same thing.