Area codes 215 and 267
Area code 215 was one of the original area codes established in 1947 and originally included the entire southeastern part of the Commonwealth, from the Delaware border to the Lehigh Valley. Pennsylvania was divided into four numbering plan areas, after New York state the most in the Bell System, together with Illinois, Ohio, and Texas.
On January 8, 1994, the area served by 215 was split. Most of its western portion, i.e. Philadelphia's southern and western suburbs, most of Berks County and the Lehigh Valley, changed to area code 610, while Philadelphia and its northern suburbs remained 215. However, three central office codes were moved from 215 to 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 all served by non-Bell telephone companies which sought to consolidate their eastern Pennsylvania customers into one area code, and would have had to change area codes anyway. The codes 267 and 484 were later used for overlay area codes in 215 and 610 respectively.
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. The supply of numbers was further limited because the entire state of Delaware is part of the Philadelphia LATA, meaning several exchanges in Delaware's 302 weren't available for use. To solve the problem, overlay code 267 was established July 1, 1997. Local calls across the Delaware/Pennsylvania border have been changed to 10-digit dialing to remove some restrictions on prefix assignments.
Area code 445 was first proposed in July 2000 as an overlay with area codes 215 and 267. However, these plans were delayed and then rescinded in 2003 by the Pennsylvania Public Utility Commission. The need for new phone numbers in area codes 215/267 was delayed until 2018. In December of 2016, it was announced that area code 445 will be activated as an additional overlay area code on March 3, 2018. 
The 215/267 area codes serve all or part of five counties in Pennsylvania.
- Berks County (extreme eastern portion)
- Bucks County (all but northeastern portion, which is served by 610/484)
- Lehigh County (extreme southern portion)
- Montgomery County (northern and eastern area, rest of county served by 610/484)
- Philadelphia County (all)
Places with over 30,000 inhabitants
- "NPA 445 to Overlay NPAs 215 and 267 (Pennsylvania) / NPA 835 to Overlay NPAs 610 and 484 (Pennsylvania)" (PDF). (582 KiB)
- "NPA 445 Implementation for 215/267 NPA Rescinded — 445 NPA Code Reclaimed" (PDF). (64.5 KiB)
- "NPA 445 to Overlay NPAs 215/267 (Pennsylvania)" (PDF). (1.1 MiB)
- Area Code 215 and 267 Map (PDF) (Map). Pennsylvania Public Utility Commission. Retrieved June 22, 2011.
- List of Pennsylvania area codes
- NANPA Area Code Map of Pennsylvania
- List of exchanges from AreaCodeDownload.com, 215 Area Code
- List of exchanges from AreaCodeDownload.com, 267 Area Code
|Pennsylvania area codes: 215, 223, 267, 272, 412, 484, 570, 610, 717, 724, 814, 878|
|North: 484/610, 908|
|West: 484/610||215/267||East: 609|
|New Jersey area codes: 201, 551, 609, 732, 848, 856, 862, 908, 973|