Area Code 24 – Hanoi City

Overview of Vietnam Area Code 24

Area code 24 is the national destination code (NDC) assigned to Hanoi, the capital city of Vietnam. It is a geographic code, meaning it corresponds to a specific administrative region, in accordance with the ITU-T E.164 numbering plan. Hanoi is the political, cultural, and economic center of the country, hosting numerous government institutions, foreign embassies, corporate headquarters, and a dense network of businesses. The code 24 replaced the older 4-digit area code (04) on 11 February 2017, as part of Vietnam's national numbering plan reform to standardize subscriber numbers to 8 digits after the trunk prefix.

Geographic Coverage and Dialing Formats

The 24 area code covers the entire Hanoi metropolitan area, including its central urban districts (such as Hoan Kiem, Ba Dinh, Dong Da, Hai Ba Trung) and the extended suburban and rural districts that are administratively part of the city. When dialing a landline in Hanoi, the national format is 0-24-XXXXXXX (where X represents the 8-digit subscriber number). Internationally, callers must omit the leading trunk prefix '0' and dial +84-24-XXXXXXX. For example, a typical Hanoi landline number might be +84 24 3829 1234.

Calling Instructions

• Domestic calls from other provinces: Dial the trunk prefix '0', then the area code 24, followed by the 8-digit subscriber number. Example: 024 3829 1234.
• International calls from abroad: Dial your country's exit code (e.g., 00, 011), then Vietnam's country code +84, then the area code 24 (without the leading '0'), followed by the subscriber number. Example: +84 24 3829 1234.
• Local calls within Hanoi: For calls between landlines in the same area code, the full 8-digit subscriber number is dialed directly (without the area code). However, for clarity and to avoid confusion with mobile numbers, many users still dial the full national format.

Overlay and Numbering Considerations

Hanoi does not currently have an overlay area code; the 24 code is exclusive to the city. The subscriber number length is fixed at 8 digits, which provides a capacity of up to 100 million numbers, ample for the city's needs. In 2017, the change from 04 to 24 was mandatory, and all old numbers were migrated seamlessly. Callers should be aware that while the area code is geographic, VoIP and mobile numbers are non-geographic and are prefixed with other codes (e.g., 3, 5, 7, 8, 9 for mobile). Therefore, a number starting with +84 24 is always a fixed-line service in Hanoi.

Practical Tips for Callers

When saving Hanoi numbers in your phone, always store them in international format (+84 24 ...) to ensure correct dialing from anywhere in the world. If you are traveling to Vietnam and need to call a Hanoi landline, you can use the national format with the leading '0' when dialing from within Vietnam. For business purposes, ensure that your contact lists and systems are updated to the new 8-digit format to avoid misdialing.