Editing Ten-digit dialing (section)

==1+10 dialing==
Long-distance calls within a numbering plan area may also require dialing of an extra leading digit, designated as ''1+10D''. This became standard in all of North America by beginning of 1995 to allow introduction of [[interchangeable NPA codes]], which are area codes that did not have a 0 or 1 as the middle digit and could therefore be confused with the central office code.

Dialing ''1'' before the area code is most often required only for long-distance calls. Some telephone systems in early overlay areas do not accept a "1" before the area code for local calls; all Canadian landlines follow this pattern. However, in metropolitan [[New York City]] and [[Chicago]], as well as the entire state of [[California]], the initial "1" is required even for local calls for landline phones located within an overlay complex or with a single NPA that also serves customers with a 988 NXX (see below). All cellphones in North America ignore this and only require the user to dial ten digits.<ref>{{cite web|url=http://www.verizon.com/MultiMedia/areacodes/dialing_instructions.aspx|title= Dialing Instructions|publisher=Verizon}}</ref>