State data show that about half of Illinois households only have wireless phone service.
The Illinois Commerce Commission says 48 percent of households in the state relied on wireless-only service at the end of last year.
Landline use has dropped 36 percent in Illinois from 2005 to 2014. There are about 5 million landline users in Illinois, including Internet- and cable-based lines.
The state has about 13 million wireless subscribers, the commission estimates.