Our invoices might seem complicated at first glance but once you understand few key points there should be no doubt about how it works. Main thing to know is that you always pay exactly for what you use.
At the billing day we charge you a forward fee for the next month, where the fee is calculated from the account usage on the billing day and at the same time we settle the forward fee from the last month by fully returning it first and then listing all your actual usage of the account during the last month and its prices.
For example if you should have 5 additional agents for 1 week then you pay only aliquot payment for this usage, you wouldn't pay the full monthly price for 5 agents but you would pay only a quarter of it, so only the aliquot part.
Every time you change the usage of the account, like when you add or remove agents, a new invoice line is added.
Let's have a real example with the following invoice:
First section of the invoice is "Prepayment for new period" which is the forward fee for the next month calculated on current usage of the account on the billing day. In the time this customer started his All-in-one plan its cost was 51€ a month and each additional agent was 22€ a month. At the billing day he was using 119 additional agents so the prepayment was calculated as 51€ + 119*22€.
Second part is "Settlement of last billing period" which might be the most confusing. It always starts with the return of the forward fee from the last billing period and then continues with the usage list of the account and the appropriate prices.
"Prepayment for new period" part on previous invoice of this customer was 1034€ which is first returned to the customer during the settlement calculation and then the usage list is added. You can see how additional agents were gradually added to the account and that we always charge you only for the given usage period.
For example notice the 16 additional agents on September 28. At this particular day the customer had 16 additional agents so the payment is calculated as 22€ * 16 agents / 30 days and rounded down for the final 11,73€.
Third part - "Discounts" - is optional and contains various applied discounts for the subscription. As you can see this customer took advantage of a very limited time period offer of 33% and he did well since he now saves more than 1000€ a month.
The last part of the invoice is the sum of all the above items.