Hi pacetree,
Does the local carrier have instructions on how to port numbers? Our porting instructions are pretty generic, wherein you keep your previous phone service where your desired phone number resides until you complete the porting process. So if you're leaving the HN Voice service for something else, I would believe the steps are the same. Check with your new carrier if they have a porting form you need to fill out to initiate the porting process. Once your number has been ported, then you can safely cancel your HN Voice service.