We've adapted, consciously or not, to a small oddity of our phone system: When you make a long-distance call on a landline phone, you need to dial 1 before the number. On most wireless phones, the 1 is superfluous. But if you include the 1 in a wireless call, that's okay—the phone can cope. In short, the cell-phone system seems smarter; the wired system seems strangely fussy. Why?
The landline network still requires a 1 for reasons of history, business, and regulation. Adam Newman, an engineer for Telcordia, which provides software to run the system, says most states still "require the local exchange to provide a toll indicator"—traditionally the 1—as a warning to consumers that calls will cost more. Switches in the landline world, moreover, still listen to the number as you dial it. As soon as the network hears you dial 1, the call is sent to long-distance lines to be completed. So "there's no technical reason the 1 couldn't come out," says Bob Azzi, vice president of network engineering for Sprint. "But you've got thousands of local-phone providers, thousands of switches, all of which would have to be changed."
Which makes the 1 a bemusing modern quirk: unnecessary, but required.