Area Code 531 – Sampit

Overview of Area Code 531 (Sampit, Indonesia)

Area code 531 is a geographic National Destination Code (NDC) assigned to the city of Sampit and its surrounding administrative regency, Kotawaringin Timur (East Kotawaringin), in the province of Central Kalimantan (Kalimantan Tengah), Indonesia. This code is part of the Indonesian national numbering plan, which follows the ITU-T E.164 recommendation. The international dialing format for a fixed-line number in Sampit is +62 531 XXX XXXX, where the leading '0' of the domestic trunk prefix is omitted when dialing from abroad.

Geographic Coverage and Administrative Jurisdiction

The 531 area code serves the capital of Kotawaringin Timur Regency, Sampit, which is a significant economic hub on the southern coast of Borneo. The coverage extends to the regency's administrative districts, including Mentawa Baru Ketapang, Baamang, and Seranau, among others. Sampit is known for its port and palm oil industry, and the area code is used for all fixed-line telephone services (PSTN) within this region.

Dialing Formats and Caller Instructions

For local callers within Indonesia (excluding the Sampit area), the domestic dialing format is 0531 XXX XXXX. When calling from within the same area code, local numbers may be dialed without the area code, depending on the specific service provider's configuration. For international callers, the correct format is +62 531 XXX XXXX. It is crucial to replace the leading '0' with the international access code and country code (+62). For example, to call a Sampit landline number 123 4567, an international caller would dial +62 531 123 4567.

Overlay and Numbering Considerations

Currently, there is no overlay area code for Sampit; the 531 code remains the sole geographic identifier for the region. However, as with many Indonesian regions, the number of digits after the area code may vary (typically 5 to 7 digits) depending on the density of subscribers. Callers should verify the exact number length with the recipient or local directory services.

Important Notes for Callers

• International calls: Always use the plus sign (+) when dialing from mobile phones, or the appropriate international access code (e.g., 011 from the US) followed by 62 and 531.
• Domestic calls: When calling from outside the 531 area, dial 0, then 531, followed by the local number.
• Mobile numbers: This area code is not used for mobile services; Indonesian mobile numbers begin with prefixes like 0811, 0812, etc., and are non-geographic.