Dialing Plans
Dialing plans vary from place to place depending on whether an area has overlays (multiple codes serving the same area) and whether the jurisdiction requires toll alerting (a leading 1 for toll calls). The NANPA's web site includes dialing plan information in its information on individual area codes.
The standard dialing plan in most cases are as follows:
| Local within area code | Local outside area code | Toll within area code | Toll outside area code | |
|---|---|---|---|---|
| Single code area, with toll alerting | 7D | 7D or 10D | 1+10D | 1+10D |
| Single code area, without toll alerting | 7D | 1+10D | 7D or 1+10D | 1+10D |
| Overlaid area, with toll alerting | 10D | 10D | 1+10D | 1+10D |
| Overlaid area, without toll alerting | 10D or 1+10D | 1+10D | 10D or 1+10D | 1+10D |
Most areas allow permissive dialing of 10D or 1+10D even for calls that could be dialed as 7D. The number of digits dialed is unrelated to whether a call is local or toll when there is no toll alerting. Allowing 7D local dialing across an area code boundary (which is uncommon today and only possible with toll alerting) requires NXX protection on the other side to avoid dialing conflicts.
Most areas permit local calls to be dialed as 1+10D except for Texas, Georgia, and some jurisdictions in Canada which require that landline callers know which numbers are local and which are toll, dialing 10D for all local calls and 1+10D for all toll calls.
In almost all cases, operator-assisted calls require dialing 0+10D.
Read more about this topic: North American Numbering Plan
Famous quotes containing the words dialing and/or plans:
“Although I will inherit darkness
I will keep dialing left to right.
I will struggle like a surgeon.
I will call quickly for the glare of the moon.
I will even dial milk.”
—Anne Sexton (1928–1974)
“Man you ought to see his plans for allsteel buildins. He’s got an idea the skyscraper of the future’ll be built of steel and glass. We’ve been experimenting with vitrous tile recently... crist-amighty some of his plans would knock you out... He’s got a great sayin about some Roman emperor who found Rome of brick and left it of marble. Well he says he’s found New York of brick an that he’s goin to leave it of steel... steel an glass.”
—John Dos Passos (1896–1970)