If you receive a call from a VoIP phone number, there's no need to panic. It might be a friend without access to their regular cell phone or a business you've permitted to contact you. For example, if you’re looking to purchase a new home and you add your contact information to the inquiry phone, the realtor may add your information to their VoIP system. Essentially, it just means they’re using VoIP technology to call you and not a traditional cell phone or landline.