Area Code 4220 – Kokubunji, Tokyo
The phone area code for Kokubunji, Tokyo is 4220 (international format +814220). Browse local exchange codes (NXX) and carrier assignments below.
📍 Geographic Location of Kokubunji, Tokyo
Overview of Area Code 4220
Area code 4220 is a geographic National Destination Code (NDC) within the Japanese telephone numbering plan, assigned to the city of Kokubunji in the western part of the Tokyo Metropolis. When dialing from abroad, the full international format is +81 42 20XX XXXX, where the leading zero of the domestic trunk prefix is omitted. Within Japan, callers must dial 042-20XX-XXXX, including the trunk prefix '0'. This code is part of the broader Musashino-Mitaka numbering area, which covers several cities in the Tama region, including Kokubunji, Koganei, and part of Chofu.
Geographic Coverage and Administrative Jurisdiction
Kokubunji is a city located approximately 30 kilometers west of central Tokyo, serving as a residential and commercial hub. The area code 4220 specifically covers the central and southern districts of Kokubunji, including areas around JR Kokubunji Station, which is a major railway junction on the Chuo and Musashino lines. The city is known for its educational institutions, such as Tokyo University of Agriculture and Technology, and for its cultural landmarks like the historic temple of Kokubunji-ji. The administrative jurisdiction falls under the Tokyo Metropolitan Government, but for telecommunication purposes, it is part of the Kanto region's numbering plan.
Dialing Formats and Caller Instructions
For local callers within the same numbering area (i.e., dialing from another number with the 042 prefix), the area code is often omitted, and only the 8-digit subscriber number is dialed. However, for clarity and to avoid misdialing, it is recommended to always include the full number. For callers from other regions in Japan, dial 042-20XX-XXXX. For international callers, dial +81 42 20XX XXXX. Note that the area code 4220 is not an overlay; it is a distinct code within the 042 block, and no overlay codes have been introduced in this region as of the latest ITU-T recommendations.
Technical Considerations
All numbers under area code 4220 are fixed-line (PSTN) numbers, typically provided by NTT East, though alternative carriers may offer services via number portability. The subscriber number length is 8 digits, with the first digit after the area code typically being '2' or '3' in this specific range. Calls to these numbers are routed over the public switched telephone network, and VoIP services may also use them, but the geographic association remains. For emergency services, callers must dial 110 (police) or 119 (fire/ambulance), regardless of the area code.
When contacting businesses or residents in Kokubunji, always verify the correct 8-digit number, as the area code 4220 is just one of several within the 042 block. Misdialing may connect you to a different city in the Tama region.