There are three ways of online payments you can use:
This function is only available in our FastBill Pro accounts. To use direct payments online, you need to activate Online - Invoices: Settings | Invoice Options and enter your credentials with the appropriate payment method.
Send the invoice to your client. The mail will contain a weblink directing to "Online Kundencenter", where your client can pay immediately. If a payment is created, the invoice's status will be set to paid.