Area Code 511 – Banjarmasin

Geographic Coverage and Administrative Jurisdiction

The area code 511 is a geographic National Destination Code (NDC) assigned to the city of Banjarmasin, the capital of the province of South Kalimantan (Kalimantan Selatan), Indonesia. It serves the greater Banjarmasin metropolitan area, including the administrative city itself and its immediate surroundings, such as Banjarbaru and parts of Banjar Regency. As a geographic code, it is tied to a specific PSTN exchange area, and calls to this code are routed based on the physical location of the called line.

Dialing Formats and Usage

When calling a fixed-line number in Banjarmasin from within Indonesia, the trunk prefix 0 is used, followed by the area code 511 and the subscriber number. For example, a local number might be 0-511-XXXXXXX. From abroad, callers must use the international prefix (typically + or 00), followed by Indonesia's country code 62, then the area code without the leading zero, and the subscriber number: +62 511 XXXXXXX. It is essential to drop the initial '0' when dialing from outside Indonesia.

Numbering Structure and Length

Subscriber numbers in the 511 area code typically consist of 7 to 8 digits, excluding the area code. The total length of a national significant number (NSN) for Indonesia is usually 10 to 12 digits, including the leading '0' and area code. For example, a complete national number might be 0511-XXXXXXX, which becomes +62 511 XXXXXXX in international format. The exact length can vary depending on the operator and the specific exchange.

Overlays and Numbering Changes

As of the latest ITU-T recommendations and national numbering plan updates, there are no overlay codes for the 511 area. The code remains exclusively assigned to Banjarmasin and its immediate vicinity. However, with the growth of VoIP and mobile services, some numbers may be technically reachable via IP-based networks, but the geographic significance remains for routing and tariff purposes.

Caller Instructions

Local callers within Banjarmasin can often dial the subscriber number directly without the area code, depending on the local dialing plan. However, for clarity and to avoid misdialing, it is recommended to always include the area code. Domestic callers from other parts of Indonesia must dial 0-511-XXXXXXX. International callers should dial +62 511 XXXXXXX, replacing the leading zero with the country code. It is advisable to check with your telecom provider for any specific dialing requirements, especially when calling from mobile networks.