Beyond paying full price for a phone, another disadvantage is that consumers on prepaid plans sometimes pay more per minute than they would on a contract, according to Storey. And while contract plans typically offer a discount for a family or business plan, prepaid plans often don't. However, whether you're switching to another contract carrier or a prepaid plan, phone numbers are typically transferable.
[Read: 6 Secrets of Cellphone Carriers.]
Before switching phone plans, consider how you use your phone. Do you make calls for emergencies only? Or you do you send hundreds of texts per month? Storey says discussing your needs with your carrier can help you find the plan that makes the most sense for you.
Also do your homework on which phones work with your carrier's technology. "If you're going be buying a phone from one place, be certain the technology of the phone matches the technology that the carrier uses," Greengart says. "Device portability doesn't always work, depending on which carrier your device was designed for and which carrier you're going to."