Area codes 215, 267, and 445 are telephone area codes in the North American Numbering Plan (NANP) for Philadelphia and adjacent portions of Bucks and Montgomery counties in the U.S. state of Pennsylvania.
On January 8, 1994, the western and northern portions of the original 215 territory, including Philadelphia's western suburbs, most of Berks County, and the Lehigh Valley, changed to area code 610, while Philadelphia and its northern suburbs retained 215.
However, three central office codes were moved from 215 to east-central Pennsylvania's 717, namely 267 in Denver, 484 in Adamstown and 445 in Terre Hill, with 215-267 becoming 717-336 because 717-267 was already in use.
These exchanges were originally slated to move into 610, but were served by non-Bell telephone companies which sought to consolidate their eastern Pennsylvania customers into one area code.
This was intended as a long-term solution, but within two years 215 was close to exhaustion due to the rapid growth of the Philadelphia area and the proliferation of cell phones and pagers.