551 Area Code – Jersey City, New Jersey: Location, Time Zone & History

Area code 201 traces back to 1947, when it was assigned to the entirety of New Jersey as one of the original 86 area codes created under the first North American Numbering Plan — making it the very first NPA code put into service nationwide. Over the following decades the territory was repeatedly divided: a 1956 split reduced 201 to the northern part of the state, a 1991 split carved out area code 908 for central New Jersey, and a 1997 split removed Essex, Passaic, Morris, and Sussex counties into area code 973, leaving 201 with only Hudson and Bergen counties.

By the turn of the century those two counties were running short of numbers, and rather than splitting the territory again, regulators introduced 551 on December 29, 2001 as an overlay across the same Hudson and Bergen footprint as 201, with mandatory 10-digit dialing beginning December 1, 2001. The change let Jersey City, Hoboken, Bayonne, Union City, Hackensack, and other Bergen and Hudson communities keep growing without redrawing county boundaries again.

The area is known for financial-services back-office operations, logistics tied to port shipping, healthcare, and media and technology employers. Jersey City in particular is often called "Wall Street West" for the concentration of financial firms that relocated their back-office functions there from Manhattan, many after the September 11, 2001 attacks — coincidentally the same year 551 entered service.