Area codes 506 and 428 are the telephone area codes in the North American Numbering Plan (NANP) for the Canadian province of New Brunswick. Area code 506 was created in 1955 in a split of numbering plan area (NPA) 902. Area code 428 was added to the same numbering plan area in 2023 to form an overlay plan of the area.
The Maritimes provinces (New Brunswick, Nova Scotia, Prince Edward Island) were designated as a single numbering plan area (NPA) in 1947, when the American Telephone and Telegraph Company (AT&T) published the results of the design of a new telephone numbering plan for the North American continent, that unified all existing local numbering system into what would later develop into the North American Numbering Plan, with the goal of automating the expanding toll call routing that involved many telephone operators manually relaying calls across the nations. Of the set of eighty-six original North American area codes, Canada received nine, in which the Maritimes were represented by area code 902.
After the addition of Newfoundland in 1949, New Brunswick and Newfoundland were split off from the numbering plan area in 1955 with area code 506. This configuration existed only until 1962, when Newfoundland was assigned area code 709, leaving New Brunswick as a distinct numbering plan area, with area code 506. Since this persists until today without any overlay code, seven-digit dialing will remain possible in these numbering plan areas: 709, 807, and 867 in Canada, through mid-2023.
Area code 506 was expected to face numbering exhaustion in 2020, and was to be overlaid with area code 428, beginning November 21, 2020, with permissive ten-digit dialing to start in May 2020.[1] Later, the projected exhaust date was delayed to April 2023 and the implementation date was postponed to April 23, 2022.[2] However, the projected exhaust date was delayed to December 2023 and the implementation became mandatory on April 29, 2023, at midnight. Since mid-April, recorded messages have passed on to callers dialling the old method.[3]
The incumbent local exchange carrier for area code 506 is Bell Aliant, which was produced from a merger that included NBTel. Since 2005, local telephone service through Eastlink Communications has also been available in the town of Sackville.