Jailbreaking has nothing to do with whether or not you can use the iPhones on an account. All you have to do is go to a rep or just go online to the activatephone page of Verizon Wireless and just input your information and it'll activate the phone on the number that you typed in assuming it's a Verizon native iPhone. Jailbreaking lets you access the roots of the device and allows you to tinker with tweaks and such.