Area Code 57 – Chiayi/Yunlin

Overview of Taiwan Area Code 57

Area code 57 is a geographic National Destination Code (NDC) within the Taiwan telephone numbering plan, assigned under the international country calling code +886. It serves the administrative regions of Chiayi County, Chiayi City, and Yunlin County, located in the southwestern part of the island. This code is used for fixed-line (PSTN) services, including traditional copper-line telephony and increasingly VoIP-based fixed services.

Geographic Coverage and Administrative Jurisdiction

The 57 area code encompasses a mix of urban and rural areas. Key cities and towns include Chiayi City (the former provincial city), Douliu City (the county seat of Yunlin), and Taibao City (the county seat of Chiayi County). The region is known for its agricultural output, scenic Alishan mountain area, and the coastal plains along the Taiwan Strait.

Dialing Formats

For domestic calls within Taiwan, the trunk prefix 0 is used before the area code. The local subscriber number (SN) length varies from 6 to 7 digits, depending on the specific exchange and historical allocation. The complete domestic dialing format is:

• 0-57-XXXXXXX (for calls from other areas in Taiwan)
• 57-XXXXXXX (for local calls within the same area code, often omitting the trunk prefix and area code)

For international callers, the format is:

• +886-57-XXXXXXX (when dialing from abroad, drop the leading 0)

For example, a typical number in Chiayi might be +886 5 234 5678 (note: the actual number length may vary; the example uses a 7-digit subscriber number).

Overlay and Numbering Plan Considerations

Taiwan's numbering plan is administered by the National Communications Commission (NCC). As of the latest updates, there are no overlay codes for the 57 area; the code is exclusively assigned to the Chiayi/Yunlin region. However, with the migration to IP-based telephony, some fixed-line numbers may be portable to other operators, but the geographic significance remains for routing and emergency services.

Caller Instructions

Local callers within the 57 area can often dial just the subscriber number for local calls, but for clarity and to avoid misdialing, it is recommended to include the area code. Domestic callers from other regions must dial 0-57 followed by the subscriber number. International callers should dial +886 then 57 and the subscriber number, omitting the leading 0. Always check with your service provider for any specific dialing requirements, especially when calling from mobile phones or VoIP services.