Area codes 740 and 220
The numbering plan area (NPA) includes the cities of Cadiz, Athens, Belpre, Chillicothe, Circleville, Coshocton, Delaware, Gallipolis, Heath, Ironton, Jackson, Lancaster, Laurelville, Logan, Marietta, Marion, Mount Vernon, Nelsonville, Newark, Newcomerstown, Pataskala, Portsmouth, Rockbridge, Steubenville, Washington Court House, and Zanesville, Shadyside and the surrounding areas.
Area code 740 was established on September 11, 1997; it split from area code 614 on November 8, 1997.
On November 7, 2013, it was announced that the 740 area code would run out of numbers sometime in 2015.
The Public Utilities Commission of Ohio chose to remedy the situation by implementing an overlay with area code 220, effective April 22, 2015.
This requires all calls within the numbering plan area to be dialed using the full ten-digit telephone number.
Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Area codes 740 and 220.