Area codes 631 and 934


Area codes 631 and 934 are the telephone area codes for Suffolk County, New York, comprising mainly the central and eastern part of Long Island. Area code 631 was created in 1999 as a division from area code 516, and 934 was added as an overlay in 2016. Communities within the plan area include Babylon, Brookhaven, Huntington, Patchogue, Riverhead, Smithtown, Shelter Island, and the area of The Hamptons.

History of Suffolk County area codes

1947–1951: 914

With the introduction of the North American Numbering Plan during October 1947, Suffolk County, Nassau County, the lower Hudson Valley, and some areas adjacent were assigned area code 914.

1951–1999: 516

During 1951, area code 516 was assigned to Suffolk and Nassau, which were separated thereby from area code 914.

1999–2016: 631

On November 1, 1999, area code 631 was created solely for Suffolk County, to satisfy the increased need for telephone numbers mainly due to cellular services, while Nassau County retained area code 516. Permissive dialing for numbers in 516 across Long Island continued until the spring of 2000.

2016–present: 934 overlay

On July 16, 2016, area code 934 was created to overlay 631, which was nearing depletion. This was the first overlay area code for an area in the state of New York outside New York City and required 10-digit dialing for both area codes, effective June 18, 2016.