Tagged billing

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

The first day, last day and length of the calendar month containing a date.

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

Calculate a complete invoice: line nets, VAT per line, totals and a VAT summary grouped by rate.

Net total for one invoice line: unit price by quantity, less a discount.

A subscription renewal invoice: plan, add-ons and usage, coupon discounts by billing period, and VAT.

When a free trial ends and the first payment is due, from the trial's start date and length in days.

Price metered usage against tiers, graduated or volume, with an optional flat fee per tier.

Round a duration in minutes to a billing increment such as 6 or 15 minutes, up, down or to nearest.