Area code 631 serves Suffolk County on Long Island, New York, including towns such as Huntington, Islip, Brookhaven, and Riverhead. It was created in 1999 from a split of area code 516 to better manage the growth in the eastern part of Long Island. In 2016, area code 934 was added as an overlay, making ten-digit dialing mandatory. The region blends suburban life with coastal attractions and is known for its beaches, wineries, and tourism. 631 is widely recognized throughout the state and is used extensively in local business branding. It’s a key part of Long Island’s identity and continues to support one of the state’s fastest-growing regions.