ELI5 : why do some phone numbers require a 1 or 0 before the area code?


Especially when I’m calling customers at work, I often hear an intercept message saying something along the lines of, “this local call now requires an area code of a 1 or 0 before the 10 digit number…hang up and try again.” I sometimes get the message even if I’m calling someone with the same area code as my own phone number. Why does this happen?


That is so that you can dial long distance. Theoretically any phone number that doesn’t have your same area code requires a 1 or 0 so that the servers can flag the call as long distance.