Area code 860

Area code 860 is a telephone area code, overlaid by area code 959, that covers most of Connecticut, except its southwest, which uses area codes 203 and 475. Area code 959 was originally announced in August 1999, to overlay area code 860 when the 860 code nears exhaustion, starting in August 2014. Effective November 14, 2009, all calls within Connecticut must be dialed with 10 digits beginning with the area code, including calls involving two numbers using the same area code.

The 860 area code was created on August 28, 1995, as a split from area code 203 when the latter was cut back to Fairfield County (except for the Town of Sherman) and New Haven County, plus the towns of Bethlehem, Woodbury, and a small part of Roxbury in Litchfield County. Use of 860 became mandatory October 4, 1996.

The Connecticut Department of Public Utility Control, in August 1999, proposed an area code overlay for the 860 area code; the new area code was to be 959. This proposal was postponed for nearly a decade due to number conservation measures; in September 2008, it was announced that the 959 area code would overlay 860 within two years (as of August 30, 2011, an activation date for 959 had not been announced). In March 2009, it was announced that the 203/475 overlay would be activated on December 12, 2009, with the 860/959 overlay becoming active by 2011. Even though the 959 area code did not have a specific start date, all callers in Connecticut must dial 10 digits beginning with the area code (a leading 1+ is required on toll calls originating from landlines, but is not required on local calls, nor on any calls originating from wireless phones) effective November 14, 2009, to reach another Connecticut number, including calls involving two numbers with the same area code.

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