When making or receiving calls in the United States, the area code is important information that indicates the region of the number.

The area codes representing Philadelphia and its surrounding areas are 215, 267, and 445. These three area codes operate under an overlay plan, covering the same geographical area. This means that three codes are used simultaneously in one area, and the area code alone cannot distinguish whether a number is from downtown Philadelphia or the suburbs.

215 is the oldest original area code for Philadelphia. It was designated as the code covering Philadelphia and all of eastern Pennsylvania when the North American Numbering Plan (NANP) was first implemented in 1947. Initially, it covered all of eastern Pennsylvania, but as the demand for numbers increased, several splits occurred. Currently, it is used in the City of Philadelphia and parts of Montgomery County, Bucks County, and Delaware County.

267 was introduced in 1999 as an overlay code operating alongside 215. It was added to accommodate the demand for new phone numbers within the same geographical area as the existing 215 code. With the introduction of the overlay, regulations were applied in the Philadelphia area requiring 10-digit dialing even for local calls. This means that within Philadelphia, callers must dial either 215 or 267 before the recipient's number.

445 is the third overlay code introduced in 2020. Due to the increasing demand for phone numbers from the growing smartphone usage, IoT devices, and business lines, the existing 215 and 267 codes were insufficient. The 445 code is used throughout the same coverage area as 215 and 267. All three codes are overlaid in the same area regardless of geographical location, so any code received is recognized as a Philadelphia area number.

It is also useful to know other area codes near Philadelphia. The Lehigh Valley area, including Allentown, Bethlehem, and Easton in eastern Pennsylvania, uses the 610 and 484 overlay codes. The entire state of Delaware uses the 302 code, while southern New Jersey (Cherry Hill, Atlantic City, etc.) uses 856, central New Jersey uses 609, and northern New Jersey uses 201, 551, and 973. New York City uses 212, 646, 718, 917, and 347 codes.

There are also important Philadelphia phone numbers that are practical for the Korean community to know. The main phone number for Philadelphia City Hall is 215-686-1776, the non-emergency police number is 215-686-8686, the customer service for Philadelphia Gas Works (PGW) and PECO is 215-937-6937.

In emergencies, always dial 911. If you want a Philadelphia number when opening a new phone line in the U.S., you will be assigned one of the codes 215, 267, or 445 upon request to your carrier. There is no difference in charges based on the number code, so you can use any code interchangeably.