Tagged refund

Split an amount into the part used and the part unused over a billing period, losing nothing.

Credit note against an original invoice, by units or by amount, with VAT at the original tax point's rates.

Return premium on mid-term cancellation, pro rata or on a short-period scale, with an optional minimum retained premium.

Refund for returned items, sharing basket discounts back across the sale so every refund is exact to the penny.