Area Code 371 – Sumbawa

Overview of Area Code +62 371

Area code 371 is a geographic National Destination Code (NDC) within the Indonesian public switched telephone network (PSTN), assigned under the country calling code +62. It serves the island of Sumbawa in West Nusa Tenggara province (Nusa Tenggara Barat). Specifically, it covers the administrative regencies of Sumbawa Besar and Dompu, as well as the surrounding districts on the western and central parts of the island. The city of Sumbawa Besar, the capital of Sumbawa Regency, is the primary hub for this numbering area.

Geographic Coverage and Dialing

The 371 area code is used for fixed-line telephone services, including PSTN and VoIP-based landlines, within this region. When dialing a number in the Sumbawa area from within Indonesia, subscribers must use the trunk prefix 0 followed by the area code and the subscriber number. For example, to call a fixed line in Sumbawa Besar, one would dial 0371 5XXXXX (where 5XXXXX represents the local subscriber number). The national dialing format is therefore 0-371-XXXXXX.

For international callers, the country code for Indonesia is +62, and the leading trunk prefix '0' is omitted. Thus, an international call to the same number would be dialed as +62 371 5XXXXX. It is important to note that the area code is an integral part of the national numbering plan and must always be dialed, even for local calls within the same area code, unless the network supports abbreviated dialing for local calls, which is uncommon in Indonesia.

Numbering and Overlay Considerations

Subscriber numbers in the 371 area code typically consist of 6 to 7 digits, resulting in a total national significant number (NSN) length of 9 to 10 digits when including the area code (excluding the trunk prefix). As of the latest ITU-T E.164 recommendations and Indonesian regulatory updates, there are no overlay codes or additional area codes assigned to this region. The numbering capacity is managed by the Indonesian Telecommunication Regulatory Authority (BRTI) and is allocated to fixed-line operators such as Telkom Indonesia and other licensed PSTN providers.

Caller Instructions

For local callers within the 371 area, dialing the full national format (0-371-XXXXXX) is always safe and recommended. For callers from other parts of Indonesia, the same format applies. For international callers, the format is +62 371 XXXXXX. It is essential to replace the plus sign with the appropriate international access code (e.g., 011 from the US, 00 from most European countries) when dialing from a landline.

This area code is strictly geographic, meaning that the number is tied to a physical location. However, with the advent of VoIP and number portability, some numbers may be used for non-geographic services, but the code remains associated with the Sumbawa region for regulatory and routing purposes.