Area Code 4 – Tutong

Overview of Brunei Area Code 4

Area code 4 is the geographic National Destination Code (NDC) assigned to the Tutong District of Brunei Darussalam. Under the ITU-T E.164 international numbering plan, Brunei's country calling code is +673. When dialing a fixed-line number in Tutong from abroad, callers must use the format +673 4XX XXXX, where the leading trunk prefix '0' is not used (Brunei has no trunk prefix for international dialing). Within Brunei, local calls to Tutong numbers are placed by dialing the 7-digit subscriber number directly, which begins with the digit '4'.

Geographic Coverage and Administrative Jurisdiction

The Tutong District is one of Brunei's four districts (daerah) and is administered by the Tutong District Office. The district is bordered by the South China Sea to the north, the Belait District to the west, and the Brunei-Muara District to the east. The primary administrative town is Pekan Tutong, which serves as the district's commercial and administrative hub. Other notable settlements within the code 4 area include Lamunin, Telisai, Keriam, and Rambai. The numbering area covers both urban and rural localities, with fixed-line services provided primarily by the national telecommunications operator, UNN (Unified National Networks).

Dialing Formats and Caller Instructions

For callers within Brunei, dialing a Tutong fixed-line number requires only the 7-digit number, e.g., 422 3456. There is no area code to dial separately; the leading '4' is part of the subscriber number. For international callers, the correct format is +673 422 3456 (or 011 673 422 3456 from North America). It is important to note that Brunei does not use a trunk prefix (like '0') for domestic calls, so international callers must not add any extra digit after the country code. Mobile numbers in Brunei are also 7 digits and begin with '7' or '8', so there is no confusion with geographic codes.

Overlay and Numbering Considerations

Brunei's numbering plan is non-oversubscribed, and there are currently no overlay codes in the Tutong area. The 7-digit subscriber numbering format is uniform across the country, with geographic codes 2 (Brunei-Muara), 3 (Belait), 4 (Tutong), and 5 (Temburong) allocated to fixed-line services. Number portability is not widely implemented for fixed lines, so the geographic code generally indicates the physical location of the line. As Brunei continues to modernize its telecommunications infrastructure, the transition to VoIP and NGN may affect future numbering allocations, but as of now, code 4 remains strictly geographic.