For a cooperative society
Members who ask questions deserve an answer they can hold in their hand.
A society lives on trust, and trust is easiest to keep when the arithmetic is visible. Each member's statement carries every line: the date, the milk type, the litres, the fat, the SNF, the CLR if you take it, the base rate, the bonus and the amount. Nothing is a single total that has to be believed.
You can switch on a passbook view so a supplier signs in with their own phone number and sees only their own entries, payments and balance. It is read only — they cannot change anything. If a member supplies more than one society, each appears in its own tab.
Pricing bends to the society rather than the other way round. The base rate, the standard fat and SNF, the bonus and even the rate chart can all be set for the society and overridden for one member whose terms are different.
Bills run on your cycle — seven, ten, fifteen or thirty days, or a custom length — and the cycle you are looking at rolls forward on its own.