You have to top up your account to pay for your usage throughout the month, including phone calls, outbound text messages, phone numbers, and call recording storage. Anything that is transactional within smrtPhone comes out of your credit balance.
Your credit balance is distributed across your entire team. This means that users who only use the system a little will only be charged a little, and those who use it a lot will be charged more. By charging only for what you use, we feel this is the fairest way to bill you.