Area Code 277 – Dong Thap province

Overview of Area Code 277

Area code 277 is a geographic National Destination Code (NDC) assigned to the Dong Thap province in the Mekong Delta region of southern Vietnam. This code is used for fixed-line (PSTN) services within the province, including the provincial capital Cao Lanh and other major towns such as Sa Dec and Hong Ngu. When dialing a fixed-line number in Dong Thap from within Vietnam, subscribers must use the trunk prefix 0 followed by the area code and the subscriber number. For example, a local number in Cao Lanh might be dialed as 0277 3 456 789 from other parts of the country.

International Dialing Format

Callers from outside Vietnam should dial the international access prefix (e.g., 00 or +), followed by the country code 84, then the area code 277 (without the leading zero), and finally the subscriber number. For instance, an international caller would dial +84 277 3 456 789. It is important to note that the subscriber number length for fixed lines in Vietnam is typically 7 to 8 digits, but the total length after the country code and area code must not exceed 15 digits as per ITU-T E.164 standards.

Geographic Coverage and Administrative Jurisdiction

Dong Thap province is situated on the border with Cambodia and is known for its extensive network of rivers and canals. The area code 277 covers all fixed-line subscribers within the province, including both urban and rural districts. The province is divided into several administrative units, including Cao Lanh city, Sa Dec city, Hong Ngu town, and the districts of Cao Lanh, Thap Muoi, Tam Nong, Thanh Binh, Lap Vo, Lai Vung, Chau Thanh, and Hong Ngu. All fixed-line numbers in these areas share the 277 NDC.

Local and National Dialing Instructions

For local calls within the same area code, subscribers may often dial only the subscriber number, omitting the area code, depending on the specific local exchange configuration. However, for calls from other provinces or mobile networks, the full national format 0277 followed by the subscriber number is required. Mobile phone users in Vietnam should always include the area code when calling fixed lines, as mobile numbers are non-geographic and do not require area codes.

Overlay and Numbering Considerations

As of the latest updates, there is no overlay code for Dong Thap; the 277 code is unique to the province. However, the Vietnam Telecommunications Authority periodically reviews numbering plans, and subscribers should consult their service provider for any changes. When dialing from abroad, it is essential to drop the trunk prefix '0' to avoid routing errors.