Area Code 431 – Manado/Tomohon/Tondano

Geographic Coverage and Administrative Jurisdiction

The area code 431 is a geographic National Destination Code (NDC) assigned to the northern region of Sulawesi Island, Indonesia. Specifically, it serves the city of Manado, the capital of North Sulawesi Province, along with the neighboring municipalities of Tomohon and Tondano. These areas fall under the administrative jurisdiction of the provincial government, and the code covers the districts of Manado City, Tomohon City, and Minahasa Regency (where Tondano is the capital). The numbering area is part of the Indonesian public switched telephone network (PSTN) and is managed by the national regulatory authority, the Ministry of Communication and Informatics.

Dialing Formats and Instructions

For callers within Indonesia, dialing a fixed-line number in the Manado area requires the trunk prefix 0, followed by the area code 431, and then the subscriber number. For example, a local number might be 0431-XXXXXXX (typically 7 to 8 digits after the area code). International callers must use Indonesia's country code +62, drop the leading trunk prefix, and dial +62 431 XXXXXXX. For instance, if a local number is 0431-1234567, an international caller would dial +62 431 1234567.

When calling from outside Indonesia, always replace the leading '0' with the international access code of your country, then dial 62, then 431, and the subscriber number. For calls originating from mobile phones within Indonesia, the same format applies: dial 0431 followed by the subscriber number. No additional codes are required for calls within the same area code; local calls may be made using only the subscriber number if the network supports it, but it is common to include the area code for clarity.

Overlay and Numbering Considerations

As of the latest updates, there is no overlay code for the 431 area; it remains a standalone geographic code. However, with the growth of telecommunication services, some subscribers may have migrated to VoIP or mobile networks, but the geographic code is still used for fixed-line services. If you are a business or resident in the region, ensure that your telecommunications provider has correctly assigned your number to the 431 area code to avoid misrouting.

Practical Guidance for Callers

• Local callers (within Manado/Tomohon/Tondano): You may dial the subscriber number directly if your phone system supports local dialing, but using the full national format (0431-XXXXXXX) is recommended for reliability.
• Domestic callers from other Indonesian regions: Dial 0431-XXXXXXX.
• International callers: Dial your country's exit code, then 62, then 431, then the subscriber number (omit the leading 0).

Always verify the subscriber number length, as it can vary between 7 and 8 digits. For assistance, contact your service provider or consult the official Indonesian numbering plan.