Area Code 4002 – Taichung/Changhua

Overview of Area Code +886 4002

Area code 4002 is a geographic National Destination Code (NDC) within the Taiwan numbering plan, assigned to the Taichung–Changhua metropolitan region in central-western Taiwan. This code is used for fixed-line (PSTN) services and is administered by the National Communications Commission (NCC) under the ITU-T E.164 framework. The region encompasses Taichung City, a major economic and cultural hub, and Changhua County, an important agricultural and industrial area. The code serves both urban districts and surrounding suburban and rural communities.

Dialing Formats

When calling a number in the 4002 area code, the dialing format depends on the caller's location:

• Domestic calls within Taiwan: Dial 0 4002 XXX XXX (where X represents the subscriber number). The leading '0' is the trunk prefix used for domestic long-distance calls.
• International calls from abroad: Dial the Taiwan country code +886, followed by the area code without the leading '0', and then the subscriber number: +886 4002 XXX XXX.

For example, a local call to a subscriber number 1234567 would be dialed as 04002 1234567 within Taiwan, and as +886 4002 1234567 from overseas.

Geographic Coverage and Administrative Jurisdiction

The 4002 code is part of the broader Taichung numbering area, which historically used the 4 area code (e.g., 4, 42, 43, 44). With the growth of telecommunications demand, additional NDCs such as 4002 were introduced to provide more numbering capacity. The code covers districts within Taichung City, including but not limited to Central, West, East, South, North, and surrounding districts, as well as parts of Changhua County. The administrative jurisdiction falls under the Taichung City Government and Changhua County Government, respectively.

Numbering and Overlay Considerations

Subscriber numbers under 4002 typically have a total length of 8 or 9 digits when including the area code, depending on the specific allocation. Taiwan has implemented overlay plans in some regions, meaning that multiple area codes may serve the same geographic area. However, for the 4002 code, no overlay has been introduced; it is a distinct code within the Taichung–Changhua region. Callers should always use the full 10-digit dialing format (including the leading '0' for domestic calls) to ensure proper routing, especially as number portability is available for fixed-line services.

Caller Instructions

For local callers within the same area code, dialing the subscriber number alone may be sufficient in some cases, but it is recommended to use the full national format to avoid misrouting. For callers from other regions in Taiwan, always include the trunk prefix '0' and the area code. For international callers, remember to replace the trunk prefix '0' with the country code '+886'. Ensure you have the correct subscriber number, as numbers in this region may have varying lengths.