An invoice is a calculation of all the billing items for that contract for a defined period (as configured on the contract) with deduction of possible paid advances on that contract during this invoicing period. Invoice periods can be yearly, half-yearly, quarterly or monthly.

An end-note is created when a contract is ended. It is the calculation of all the billing items for that contract from the last invoice (if there had been an invoice) to the end date of the contract. In case that no invoice had been created for that contract, it will be from the startdate of the contract to the end date of the contract. Also here any paid advances are deducted from the billing amount.

Advances are recurrent fixed amounts that are billed to the end-user/tenant of the contract. These advances are a way to spread the payment of the total costs of the contract over a larger period (usually a year, depending on the invoice period defined on the contract).

The end-user of the contract pays each advance period (usually monthly) a fixed amount and when the invoice is made; these paid advances are deducted from total amount to be paid for that year. Advances can be defined on the contract.

They can be monthly, quarterly, half-yearly or none (no advances). The periodicity of the advances should off course be lower then the periodicity of the invoicing period (which can also be monthly, quarterly, half-yearly or yearly).

An incidental note is an amount that is being billed to an end-user outside of the normal billing cycle. For example when a compensation is being given to a customer that had technical problems with his installation. We are creating an incidental note that has an amount on it to be paid to that end user. Also when we want to charge the customer of that contract with something extra for one time and that is not part of the product on the contract.

A correction note is used to correct something from an invoicing document. The distinction between incidental and correction note is only what the user of Zero Friction wants to use. On the generated document will be printed the name 'correction note' or 'incidental note'; so this is only a personal preference which one to use.

A credit nota is made when we want to cancel an entire booked invoicing document (advance, invoice, end note...). It is actually undoing the billing of the billing document it refers to. Hence, you cannot juste delete a bill that has been approved and booked on a customer; you always have to use a credit note to nulify the billing. As such the customer balance will be adjusted as well.