Area Code 331 – Feni/Sonagazi/Chagalnaiya/Daganbhuyan

Overview of Area Code +880 331

Area code 331 is a geographic National Destination Code (NDC) within the Bangladesh national numbering plan, assigned to the south-eastern district of Feni and its surrounding sub-districts: Sonagazi, Chagalnaiya, Daganbhuiyan, and Parshuram. The code is part of the Chittagong Division's telecommunication infrastructure and is administered under the Bangladesh Telecommunication Regulatory Commission (BTRC).

Geographic Coverage and Administrative Jurisdiction

The 331 area code serves the entire Feni District, which is bordered by Comilla to the north, Chittagong to the south, and the Indian state of Tripura to the east. Key towns within this code include Feni Sadar (the district headquarters), Sonagazi, Chagalnaiya, Daganbhuiyan, and Parshuram. These areas are primarily residential and commercial hubs, with a mix of agricultural and small-scale industrial activities. The code is used for fixed-line PSTN services, including traditional copper lines and some fiber-to-the-home deployments.

Dialing Formats and Caller Instructions

For international callers, the full number format is +880 331 XXX XXX, where +880 is Bangladesh's country code, 331 is the area code, and the subscriber number is typically 7 digits long. For example, a Feni landline number might be dialed as +880 331 1234567 from abroad. Local callers within Bangladesh must dial 0 331 XXX XXX (including the trunk prefix 0) when calling from outside the 331 area, but can omit the area code when dialing within the same code area (i.e., just the 7-digit subscriber number).

Overlay and Numbering Considerations

As of the latest BTRC updates, there is no overlay code for the 331 area; the code remains exclusive to Feni district. However, due to the growth of mobile and VoIP services, fixed-line penetration is relatively low, and many residents rely on mobile numbers (starting with 013, 017, 018, 019) for daily communication. For businesses, maintaining a 331 landline number can enhance local presence and trust, especially for customer service and administrative offices.

Technical Routing and PSTN Integration

The 331 code is routed through the national PSTN infrastructure, with interconnections to mobile and international gateways. Calls to 331 numbers from mobile phones require the same prefix (0 331) as from other fixed lines. For VoIP users, it is essential to configure the dialing plan correctly to include the trunk prefix and area code. International callers should be aware that Bangladesh uses a variable-length numbering plan, and the subscriber number length for 331 is fixed at 7 digits, ensuring accurate routing.

Practical Tips for Callers

• When calling from the United States or Canada, dial 011 + 880 + 331 + local number.
• From the UK, dial 00 + 880 + 331 + local number.
• Always verify the subscriber number length; if you encounter a 6-digit number, it may be an older line, but standard is 7 digits.