Area Code 220 – Hai Duong province

Geographic Overview

Area code 220 is a geographic National Destination Code (NDC) assigned to the province of Hai Duong in the Socialist Republic of Vietnam. Located in the Red River Delta region of northern Vietnam, Hai Duong is a centrally governed province bordered by Bac Ninh, Bac Giang, Hung Yen, Thai Binh, and Quang Ninh. The province is known for its industrial parks, agricultural output, and historical sites. The primary administrative and economic center is Hai Duong City, which serves as the provincial capital. Other significant urban areas include Chi Linh, Gia Loc, and Cam Giang.

Dialing Formats

When dialing a fixed-line number in Hai Duong from within Vietnam, subscribers must use the trunk prefix 0 followed by the area code 220 and the subscriber number (which is typically 7 digits long). The national format is: 0 220 XXX XXXX. For example, a local number in Hai Duong City might be dialed as 0220 385 6789 from other provinces.

For international callers, the country code for Vietnam is +84. Therefore, the international dialing format becomes +84 220 XXX XXXX, omitting the leading trunk prefix 0. For instance, a caller from the United States would dial 011 84 220 385 6789 (or +84 220 385 6789 on a mobile phone).

Calling Instructions

• Local callers within Hai Duong: If you are calling from a landline within the same area code, you may often omit the area code and dial only the 7-digit subscriber number. However, for clarity and consistency, it is recommended to use the full national format 0220 XXX XXXX.
• Callers from other Vietnamese provinces: Dial 0220 followed by the subscriber number. The trunk prefix 0 is mandatory.
• International callers: Dial your country's exit code (e.g., 00 from many countries, 011 from the US/Canada), then 84, then 220, and finally the subscriber number. Do not include the leading 0.

Numbering and Overlay Considerations

Vietnam's numbering plan is regulated by the Ministry of Information and Communications (MIC) and follows ITU-T E.164 recommendations. Area code 220 is a geographic code, meaning that the number is tied to a physical location. As of the latest updates, there are no overlay codes or 10-digit dialing requirements in Hai Duong; the standard 8-digit national format (including the trunk prefix) applies. However, with the growth of telecommunications services, it is always advisable to verify the current dialing procedures with your service provider.

Fixed-line numbers in Vietnam are increasingly used for both PSTN and VoIP services, but the geographic significance remains for routing and emergency services. When calling from abroad, ensure you have the correct country code and area code to avoid misdialing.