Area Code 201

Area code 201 is the first numbering plan area (NPA) code ever assigned in the North American Numbering Plan, established in 1947 when AT&T devised the nationwide telephone numbering system. Originally covering the entire state of New Jersey, it has undergone three geographic splits over 50 years and one overlay, reducing its territory from the full state to just Hudson and Bergen counties — the two most densely populated counties in New Jersey. Source: Wikipedia — Area codes 201 and 551

• 1947: Area code 201 is established as the first NPA code assigned in the entire North American Numbering Plan. It covers the entire state of New Jersey, despite NJ having the highest population density in the nation. The middle digit "0" in the N0X format indicated statewide coverage under the original pre-1953 numbering convention. Source: Wikipedia Source: AboutAreaCode.com
• November 10, 1951: The first customer-dialed long-distance telephone call in history is made from Englewood, New Jersey. Mayor M. Leslie Denning dialed 10 digits to reach Alameda, California Mayor Frank Osborne. The call completed in 18 seconds without operator assistance. Englewood was selected because of its modified switching system at the Engle Street central office that enabled direct dialing throughout New Jersey and parts of New York. Source: Wikipedia
• 1956: The first split of 201 occurs. New Jersey is divided into two numbering plan areas: area code 201 retains northern New Jersey, while area code 609 is created for central and southern New Jersey (from Trenton southward, including the Jersey Shore and Delaware Valley suburbs). Despite the split, 7-digit dialing within New Jersey continues until 1963. Source: List of NJ Area Codes
• July 21, 1963: Office code protection ends in New Jersey. Area codes become mandatory for all calls between the two numbering plan areas (201 and 609). Prior to this date, all NJ calls could be made with 7-digit dialing. Source: Wikipedia
• January 1, 1990: Area code 908 is created from the southern portion of the 201 plan area. The split, announced by Bellcore in September 1989, carved off Hunterdon, Middlesex, Monmouth, Ocean, Somerset, Union, and Warren counties. Permissive dialing ends June 8, 1991. Source: NANPA Planning Letters
• June 1, 1997: Area code 973 is created from 201. Essex, Passaic, Morris, and Sussex counties are split off. This leaves area code 201 serving only Hudson and Bergen counties — the two most densely populated counties in New Jersey and closest to New York City. Source: Wikipedia Source: AboutAreaCode.com
• March 2001: The New Jersey Board of Public Utilities (BPU) approves three new overlay area codes: 551 over 201, 862 over 973, and 848 over 732. Verizon, the dominant telephone company in New Jersey, specifically lobbied for an overlay rather than a geographic split to avoid forcing customers to change their phone numbers. Source: NJ BPU Consumer Handbook 2006
• December 2001: Area code 551 is activated as an overlay for 201. Ten-digit dialing becomes mandatory in the 201/551 region. This was part of a broader implementation that also included 862 overlaying 973 and 848 overlaying 732, making ten-digit dialing mandatory throughout northern New Jersey. Source: ZIP-Codes.com

The regulatory history of area code 201 spans the full evolution of the North American Numbering Plan, from AT&T's original 1947 numbering scheme through the FCC's delegation of numbering authority to state commissions under the Telecommunications Act of 1996. The New Jersey Board of Public Utilities (BPU) holds primary jurisdiction over numbering matters in New Jersey, and all major relief actions for the 201 NPA have involved BPU regulatory proceedings. Source: Wikipedia — Area codes 201 and 551