Ringback tones on an iPhone play sound clips or songs for a caller to hear instead of ringing while they're waiting for the individual they called to answer the phone. They play over the cellular network, and are not stored on the iPhone.
Individuals who have AT&T as their cellular provider can purchase an app that is specifically for ring-back tones. As of 2015, there was a 99-cent subscription fee for this service. If phone owners have Sprint as their cell provider, there is also an app they can download to their phone. Sprint allows customers to preview the song before they purchase it for their ringback tone. Sprint allows customers to customize their tones based on the individual who is calling. Sprint also charges customers a subscription fee for this service.
Customers with T-Mobile can purchase their ringback tones by browsing the T-Mobile website. Customers can listen to a track before committing to purchase it, and can also assign certain ring-backs to groups or contacts. Those with Verizon can log into the Verizon Media store and search to purchase ringback tones. There is also an option to purchase groups of songs to be used as ringback tones in one bundle.