Area Code 221 – Hung Yen province

Overview of Area Code +84 221

Area code 221 is the National Destination Code (NDC) assigned to the province of Hung Yen in the Socialist Republic of Vietnam. Under the ITU-T E.164 international numbering plan, the full international dialing format for a fixed-line subscriber in Hung Yen is +84 221 XXX XXXX, where +84 is the country calling code for Vietnam, 221 is the NDC, and the following 7 digits represent the subscriber's local number. Within Vietnam, callers dial 0221 XXX XXXX (including the trunk prefix 0).

Geographic Coverage and Administrative Jurisdiction

Hung Yen is a province located in the Red River Delta region of northern Vietnam. The area code covers the entire provincial territory, including the provincial capital, Hung Yen City, and all districts such as Van Lam, Van Giang, My Hao, An Thi, Kim Dong, Khoai Chau, and Tien Lu. The province is part of the Hanoi metropolitan area's economic corridor, and its telecommunications infrastructure is integrated with the national PSTN and VoIP networks.

Dialing Formats and Caller Instructions

• Local callers (within Vietnam): To call a fixed-line number in Hung Yen from another province, dial 0221 followed by the 7-digit subscriber number. For example, to reach a number in Hung Yen City, dial 0221 386 1234.
• International callers: From outside Vietnam, dial the international access prefix (e.g., 00 or +), then 84, then 221, and the 7-digit subscriber number. For instance, an international caller would dial +84 221 386 1234.
• Local calls within the same district: In many Vietnamese provinces, local calls within the same area code may still require the full national format (including the area code) due to the implementation of closed numbering plans. It is recommended to always dial the full 10-digit national number (0221 + 7 digits) to ensure connectivity.

Numbering Plan and Overlay Considerations

Vietnam's numbering plan is regulated by the Ministry of Information and Communications (MIC). The 221 area code is a geographic code, and numbers within it are allocated to fixed-line services provided by incumbent operators such as VNPT and other licensed carriers. As of the latest regulatory updates, there are no overlay codes in Hung Yen; the 221 code remains the sole geographic NDC for the province. However, subscribers may have ported their numbers to alternative fixed-line operators, but the geographic significance of the code remains tied to the physical location of the exchange.

Practical Information for Callers

When calling Hung Yen, ensure you have the correct 7-digit subscriber number. If you are dialing from a mobile phone within Vietnam, you may need to include the trunk prefix 0 (i.e., 0221) even for local calls, as mobile networks do not automatically add the area code. For international callers, be aware that some VoIP or mobile services may require the full international format without the leading 0. Always verify the number with the recipient to avoid misdialing.