Area Code 4005 – Taichung/Changhua

Overview of Area Code +886 4005

Area code 4005 is a geographic National Destination Code (NDC) within the Taiwan numbering plan, allocated to the central-western region encompassing Taichung City and Changhua County. This code is used for fixed-line (PSTN) services, including traditional copper lines, fiber-optic broadband telephony, and ISDN services. It is important to note that this code is distinct from mobile prefixes (e.g., 09xx) and non-geographic service numbers.

Geographic Coverage and Administrative Jurisdiction

The +886 4005 code serves a densely populated area that includes Taichung, Taiwan's second-largest metropolitan area, and the surrounding Changhua County. Key cities and administrative districts covered include Taichung's central business districts (e.g., Xitun, Nantun, Beitun), as well as Changhua City and its neighboring townships. The region is a major economic hub, hosting industrial parks, technology companies, and government institutions.

Dialing Formats

Understanding the correct dialing procedure is essential for both domestic and international callers.

• Local dialing (within Taiwan): When calling a number within the same area code, subscribers typically dial only the 7-digit local subscriber number (e.g., 4005-XXXX). However, for calls from other area codes within Taiwan, the full national format is required: 0 4005 XXXX (the leading '0' is the trunk prefix).
• International dialing: Callers from outside Taiwan must dial the international access prefix (e.g., 00 or +), followed by Taiwan's country code 886, then the area code without the leading '0', and the local subscriber number. For example, to reach a number in Taichung, you would dial +886 4005 XXXX.

Overlay and Numbering Considerations

Taiwan's numbering plan has undergone several changes to accommodate growing demand. While 4005 is a specific geographic code, overlay codes may exist in the same region. In such cases, local calls may require 10-digit dialing (including the area code) even for calls within the same city. Always verify with your service provider or the local telecom regulator for the most current dialing procedures.

Caller Instructions

• For local callers (within Taiwan): If you are dialing from a different area code, remember to include the trunk prefix '0' before the area code. Example: 0 4005 XXXX.
• For international callers: Use the plus sign (+) or your country's exit code, then 886, then 4005, and the subscriber number. Do not include the trunk prefix '0'. Example: +886 4005 XXXX.

This area code is not associated with toll-free or premium-rate services; standard local and long-distance tariffs apply as determined by your telecom operator.