How to call Vietnam | In-depth guide with examples

Vietnam has emerged as one of Southeast Asia's most dynamic economies, making it an increasingly important destination for international business calls. Whether you're coordinating with manufacturing partners in Ho Chi Minh City, working with tech firms in Hanoi, or staying in touch with family members who have relocated to Vietnam, knowing how to place an international call correctly is essential. Vietnam's rapid growth in foreign direct investment and its expanding middle class have made it a hub for global commerce, and reliable communication is at the heart of that connectivity.

Beyond business, Vietnam's vibrant culture, tourism industry, and large diaspora community mean that millions of people around the world have personal reasons to call the country regularly. From confirming travel arrangements to catching up with relatives in Da Nang or Hue, international calls to Vietnam are a daily reality for a wide audience.

Guide to calling Vietnam

Before dialing, ensure you're aware of the rates charged by your carrier for international calls to Vietnam. You should also make sure your connection is reliable to avoid any issues caused by latency or choppy voice transmission.

1. Check the time in Vietnam

Vietnam is in the Indochina Time Zone (ICT), which is UTC+7. This means Vietnam is between 11 and 14 hours ahead of U.S. time zones depending on where you are and the time of year:

• Eastern Time (ET): Vietnam is 11–12 hours ahead
• Central Time (CT): Vietnam is 12–13 hours ahead
• Mountain Time (MT): Vietnam is 13–14 hours ahead
• Pacific Time (PT): Vietnam is 14–15 hours ahead

Vietnam does not observe Daylight Saving Time, so the offset shifts slightly when the U.S. changes its clocks. Always verify the local time before calling — a 9 AM call from Denver could arrive at midnight or later in Hanoi.

2. Dial the exit code

For international calls from the U.S., the exit code is 011, indicating you're making an international call. This tells your phone carrier you're dialing outside the domestic network.

3. Enter Vietnam's country code

Next, dial Vietnam's country code, which is +84, to connect your call to Vietnam. This routes your call through the international gateway and into Vietnam's national telephone network.

4. Dial the area code and local number

Start with 011, followed by 84, the country code for Vietnam.

For a landline

Vietnamese landlines use a two-digit area code followed by a seven or eight-digit local number, for a total of 10 digits (including area code). Major area codes include:

• Hanoi: 24 (e.g., 011 + 84 + 24 + XXXX-XXXX)
• Ho Chi Minh City: 28 (e.g., 011 + 84 + 28 + XXXX-XXXX)
• Da Nang: 236
• Hai Phong: 225

Drop the leading zero from the area code when dialing internationally. For example, to call a Hanoi landline with the local number 3825-6789, you would dial: 011-84-24-3825-6789.

For a mobile phone

Vietnamese mobile numbers are 10 digits long and begin with a network prefix. Common prefixes include:

• 03x: Viettel
• 07x, 08x, 09x: Various carriers (Mobifone, Vinaphone, Vietnamobile, Gmobile)

To call a Vietnamese mobile number (e.g., 0912-345-678), drop the leading zero and dial: 011-84-912-345-678.

Tips for a successful call

1. Time your calls carefully. With Vietnam being up to 14 hours ahead of the U.S. West Coast, it's easy to accidentally call in the middle of the night. Use a world clock app or website to confirm the local time in Vietnam before dialing — especially for business calls where etiquette matters.

2. Use a reliable internet connection for VoIP. If you're using Telnyx or another VoIP platform, make sure your internet connection is stable. Vietnam's telecommunications infrastructure has improved greatly, but trans-Pacific calls can still experience latency spikes on lower-quality routes. Choosing a carrier with direct peering to Southeast Asia, like Telnyx, can significantly improve call quality.

3. Be mindful of Vietnamese business customs. Vietnamese business culture places high value on respect and hierarchy. When calling for business purposes, address contacts by their formal title until invited to use first names. Avoid calling during the Tết holiday season (late January to early February) as this is the country's most important celebration and businesses typically close or operate at reduced capacity.

4. Have a backup contact method. Vietnam has very high smartphone and messaging app penetration. If a call doesn't connect or quality is poor, Zalo (Vietnam's dominant messaging app), WhatsApp, or Facebook Messenger are widely used alternatives for follow-up communication.

How Telnyx can help

International calling to Vietnam is one of many use cases where Telnyx delivers enterprise-grade voice infrastructure at consumer-grade prices. With direct carrier connections across Southeast Asia, Telnyx routes calls to Vietnam over owned network infrastructure — reducing latency, improving call clarity, and delivering rates as low as $0.01–0.05 per minute depending on destination.

Unlike traditional carriers that route calls through multiple intermediaries, Telnyx's global IP network connects directly to in-country partners, resulting in fewer hops, less jitter, and crisper audio quality. For businesses managing high call volumes to Vietnam — whether for customer support, sales, or operations — this translates into meaningful cost savings and a better experience for both callers and recipients.

Telnyx's SIP trunking platform integrates seamlessly with existing PBX and UCaaS systems, and the Mission Control Portal gives teams real-time visibility into call quality, usage, and costs. Whether you're placing a handful of personal calls or running an enterprise contact center with operations in Vietnam, Telnyx scales with your needs.

Get started with Telnyx voice services to experience the difference that owned infrastructure makes for international calls to Vietnam and beyond.