With Nextiva SIP Trunk service, we send a pro-forma invoice to the email address on file five days before the monthly recurring fee is billed to your account credit card. Nextiva service is billed at the beginning of the month and is pre-paid for the new month you are entering. The monthly recurring subscription fee is not billed in arrears.
The only arrears billing with Nextiva SIP Trunk service would be per-minute charges for our Metered SIP Trunk plan or any toll-free calls to your Nextiva SIP Trunk Account.
Example: I begin service on January 1st and am billed for the monthly subscription fees upon sign up. If I have a metered SIP Trunk plan and I use 750 minutes during January, the 750 minutes are billed, along with my next recurring subscription fee, on February 1st.