Area Code 4 – Trashigang

Geographic Coverage and Administrative Jurisdiction

The area code 4 is the National Destination Code (NDC) for the Trashigang District in eastern Bhutan. This geographic code serves the administrative town of Trashigang (also spelled Tashigang) and its surrounding gewogs (village blocks). Trashigang is one of Bhutan's largest and most historically significant districts, bordering the Indian state of Arunachal Pradesh to the south. The code covers both the urban center and the rural communities within the district, including areas along the Gamri River valley.

Dialing Formats and Caller Instructions

To call a landline in Trashigang from abroad, dial the international access prefix (e.g., 00 or +), followed by Bhutan's country code 975, then the area code 4 (without the leading trunk prefix), and finally the local subscriber number. For example, if the local number is XXXXXX, the international format is +975 4 XXXXXX.

For domestic calls from other parts of Bhutan, you must use the trunk prefix 0 before the area code: 0 4 XXXXXX. Local calls within Trashigang may be dialed using only the six-digit subscriber number, depending on the operator's network configuration. Always confirm with your service provider if local dialing requires the area code.

Numbering and Overlay Considerations

Bhutan's numbering plan follows a closed format for fixed lines: the NDC (area code) is a single digit (1 to 8), and subscriber numbers are typically six digits long. This results in a total national significant number (NSN) length of eight digits, excluding the country code. Currently, there are no overlay codes in Bhutan; each geographic area has a unique single-digit NDC. However, with the growth of VoIP and mobile services, the Bhutanese telecom regulator (Bhutan InfoComm and Media Authority) has implemented number portability for mobile services, but fixed-line numbers remain tied to geographic locations.

Practical Guidance for Callers

When calling from a mobile phone, you may need to include the area code even if you are within the same district, as mobile networks often require the full national number. For international callers, ensure you have the correct local number; do not drop leading zeros in the local number if present. Since Bhutan uses a single country code, there are no separate international dialing prefixes for different carriers.

For travelers or businesses, it is important to note that Trashigang is a remote area with limited fixed-line infrastructure; many residents rely on mobile phones. If you are trying to reach a business or government office, verify whether they have a fixed line or a mobile number. Mobile numbers in Bhutan start with 17 (e.g., +975 17 XXXXXX) and are non-geographic.