Area Code 21 – Brunei Muara
The phone area code for Brunei Muara is 21 (international format +67321). Browse local exchange codes (NXX) and carrier assignments below.
📍 Geographic Location of Brunei Muara
Geographic Overview
The area code 21 is a geographic National Destination Code (NDC) assigned to the Brunei Muara District, the smallest but most populous district in Brunei. This district hosts the national capital, Bandar Seri Begawan, along with key commercial and administrative hubs. The code covers the capital city and its surrounding suburban areas, including Kampong Ayer, Berakas, and Gadong.
Dialing Formats
When calling a landline number in Brunei Muara from within Brunei, subscribers dial the full national number, which includes the trunk prefix 0 followed by the area code and the subscriber's 7-digit local number. The national format is:
- 0 21 XXX XXXX (within Brunei)
For international callers, the trunk prefix is omitted, and the country code +673 is used. The international format is:
- +673 21 XXX XXXX (from abroad)
For example, to call a landline in Bandar Seri Begawan with the local number 123 4567, a caller in Brunei would dial 021 123 4567, while an international caller would dial +673 21 123 4567.
Administrative and Regulatory Notes
Brunei's numbering plan is regulated by the Authority for Info-communications Technology Industry of Brunei Darussalam (AITI). The country uses a closed numbering plan, meaning that all national numbers, including mobile and fixed lines, are 7 digits long after the area code. The 21 prefix is exclusively used for fixed-line services in Brunei Muara, and there are currently no overlay codes in this district. As a result, all fixed-line numbers in the district share the same 7-digit length and do not require additional digit dialing changes.
Caller Instructions
For local callers within Brunei Muara, it is essential to include the trunk prefix 0 when dialing any fixed-line number, even if calling from a nearby district. For callers from outside Brunei, the country code +673 must be dialed before the area code, and the trunk prefix is not used. Mobile and VoIP users should note that calls to this geographic code are routed over the PSTN and may incur standard international or national rates depending on their service provider.