Phone Numbers in Vietnam: A Comprehensive Guide

Quick Reference

• Country: Vietnam
• Country Code: +84
• International Prefix: 00
• National Prefix: 0

Overview

This guide provides detailed insights into Vietnam's telephone numbering plan, covering number formats, dialing procedures, and regulatory guidelines. It is an essential resource for telecom professionals, developers, and businesses aiming to understand and implement Vietnam's phone number structures accurately.

Number Formats

Vietnam's telephone numbering plan adheres to ITU-T Recommendation E.164, with the country code +84. The numbering structure includes geographic (landline), mobile, special services, and premium rate numbers.

Geographic (Landline) Numbers

• Format: 0AA X{7}
  • AA: Area code (2-3 digits)
  • X: Subscriber number (7 digits)
• Example: 028 38212345 (Ho Chi Minh City)

Regular Expression:

^0[2-9]\d{1,2}\d{7}$

Mobile Numbers

• Format: 0X X{8}
  • X: Mobile network prefix (2-3 digits)
  • X: Subscriber number (7-8 digits)
• Example: 091 2345678 (Vinaphone)

Regular Expression:

^0[3|5|7|8|9]\d{8}$

Toll-Free Numbers

• Format: 1800 X{4,6}
  • X: Subscriber number (4-6 digits)
• Example: 1800 123456

Regular Expression:

^1800\d{4,6}$

Premium Rate Numbers

• Format: 1900 X{4,6}
  • X: Subscriber number (4-6 digits)
• Example: 1900 123456

Regular Expression:

^1900\d{4,6}$

Dialing Procedures

Domestic Calls

• Landline to Landline: Dial 0 + Area Code + Subscriber Number
• Landline to Mobile: Dial 0 + Mobile Number
• Mobile to Mobile: Dial 0 + Mobile Number

International Calls

• Outgoing: Dial 00 + Country Code + Area Code (if applicable) + Subscriber Number
• Incoming: Dial +84 + Area Code (if applicable) + Subscriber Number

Number Portability

Vietnam has implemented mobile number portability (MNP) as per Circular No. 22/2014/TT-BTTTT, allowing users to retain their mobile numbers when switching between operators. This is crucial for maintaining customer satisfaction and reducing churn rates.

Major Telecom Operators and Number Ranges

Regulatory Body

The Ministry of Information and Communications (MIC) governs the telecommunications sector in Vietnam. They are responsible for the allocation, management, and regulation of phone numbers.

Recent or Upcoming Changes to the Numbering Plan

As of September 15, 2018, Vietnam transitioned all 11-digit mobile numbers to 10-digit formats. This change was mandated by the Ministry of Information and Communications to streamline the numbering plan.

Technical Considerations for Developers

When dealing with Vietnamese phone numbers in software systems, consider the following:

• Validation: Use regular expressions to validate phone numbers based on the formats outlined above.
• Normalization: Ensure that phone numbers are stored in a consistent format, preferably in E.164 format (+84 XXXXXXXXX).
• Portability: Implement logic to handle number portability, especially when integrating with telecom APIs.
• Time Zones: Vietnam operates in the Indochina Time Zone (ICT), UTC +7. Ensure time zone considerations are integrated into systems handling scheduling or time-based services.