Area codes 609 and 640

Area codes 609 and 640 are area codes for New Jersey. Area code 609 was created as a split from 201 in 1958. It initially covered the entire southern parts of the state. After being split by 856 in 1999, it now covers its state capital Trenton, Princeton, as well as other parts of southern Middlesex County, including South Brunswick. It was overlaid by 640 on September 17, 2018.

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