Area Code 25 – Brunei Muara

Overview of Brunei's Geographic Numbering Plan

Brunei Darussalam's national numbering plan adheres to the ITU-T E.164 recommendation, with a closed dialing plan for domestic calls. The country's country calling code is +673, and all subscriber numbers, including those within the Brunei Muara district, are seven digits long. The prefix '25' is a geographic National Destination Code (NDC) allocated to the Brunei Muara district, the smallest but most populous district in Brunei, which houses the capital, Bandar Seri Begawan.

Geographic Coverage and Service Area

The '25' prefix specifically serves fixed-line telephone services within Brunei Muara. This district is the administrative and economic heart of the nation, encompassing not only the capital but also major commercial hubs and residential areas such as Kiulap, Gadong, and Berakas. The numbering area covers both government and private sector landlines, with numbers typically formatted as '25X XXXX' when dialed domestically.

Dialing Formats and Instructions

For local callers within Brunei, dialing a Brunei Muara fixed-line number requires only the seven-digit subscriber number, without any trunk prefix. For example, to reach a number in the capital, one would dial 25X XXXX. There is no '0' trunk code used in Brunei, as the country uses a closed numbering plan.

For international callers, the full E.164 format must be used: +673 25X XXXX. This applies to calls originating from any country outside Brunei. When dialing from a mobile phone, the plus sign (+) is typically used, followed by the country code and the national significant number. For instance, a caller from the United States would dial 011 673 25X XXXX, while a caller from the United Kingdom would dial 00 673 25X XXXX.

Numbering Plan Considerations

Brunei's numbering plan does not currently employ area code overlays, meaning that each geographic district has a unique set of NDCs. The '25' prefix is exclusively assigned to Brunei Muara, and no other district shares this code. This simplifies dialing and routing, as the NDC directly identifies the geographic destination.

It is important to note that while the '25' prefix is geographic, the rapid adoption of VoIP and IP-based telephony in Brunei has led to some fixed-line numbers being routed over IP networks, but the geographic significance of the prefix remains for regulatory and numbering purposes.

For businesses and residents in Brunei Muara, the '25' prefix is a mark of local presence, often used by companies to establish a trusted local contact point. When displaying numbers on websites or marketing materials, it is recommended to use the international format (+673 25X XXXX) to avoid confusion for overseas clients.