857 Area Code
Area codes 617 and 857 are widely recognized as the main telephone prefixes serving Boston and surrounding communities. These codes cover neighborhoods throughout the city and are a staple of Boston’s telecommunications landscape.
Area code 617 has been part of the city’s identity since the early days of modern telephony. Introduced in 1947 under the North American Numbering Plan, it was one of the original codes assigned and originally covered a much larger portion of eastern Massachusetts. As demand for new phone numbers surged, the 857 overlay was added in 2001 to expand availability without changing existing numbers.
Today, both area codes are used interchangeably for mobile and landline numbers across Boston, from downtown to Dorchester and beyond. All major carriers, including Verizon, T-Mobile, and AT&T, operate under these codes, supporting everything from everyday communication to large-scale business operations.
617 and 857 play a crucial role in Boston’s communication network. Whether it’s a personal call, a business connection, or an emergency, these area codes keep Boston connected and responsive. They’re more than just numbers—they’re part of the city’s voice.





