Reported (631) XXX-XXXX phone numbers lookup

Area Code 631 History and Coverage

Area code 631 became operational on November 1, 1999, via geographic split from area code 516. Prior to this, 516 had covered both Nassau and Suffolk Counties. This happened after splitting the territory based on the county border whereby Nassau County continued using 516 whereas Suffolk County got 631. It was a convenient way to separate the two counties since there was increasing need for numbers within the 516 area code.

The county-level boundary led to an extensive territory being under area code 631. Beginning at the Nassau County boundary in the west and proceeding to cover central Suffolk County areas right to the eastern extremities of the county. The area code covers shoreline communities along Long Island Sound and along the Atlantic Ocean. It also covers the North and South Fork of the eastern part of Long Island. Fire Island communities under Suffolk County also lie under the same numbering plan.

There was a subsequent numbering plan change in 2016 to include area code 934 as an overlay for the same Suffolk County territory previously under 631. As compared to the previous split, the new overlay did not change the geographic territory for 631, with both codes serving the same Suffolk County region.