Short answer: No, you should not turn on data roaming when you land in Vietnam unless you already have a specific international plan from your carrier or need emergency connectivity.
In this article, we will explain in detail the question: “Should you turn on data roaming when landing in Vietnam?“, beyond the short answer above. Let’s go through what happens, what it costs, and the better alternatives for staying connected affordably.
I. Quick overview of data roaming when landing in Vietnam
Data roaming allows your home SIM card to connect to Vietnamese mobile networks for internet access through your original carrier’s roaming agreements. While this might sound convenient, it’s often the most expensive option for using mobile data abroad.
There are two main ways data roaming works:
- Pay-as-you-go (no roaming plan): charged per MB used, often the most costly.
- Pre-purchased roaming plan: includes a set amount of data valid for a few days.
If you haven’t registered a roaming plan in advance, it’s best not to turn on data roaming, even for a short layover.
II. What happens when you turn on data roaming in Vietnam
When you enable roaming after landing, your phone connects to local mobile networks – typically Viettel, Vinaphone, or MobiFone – through partnerships with your home carrier.
You will stay connected on your own phone number, but every MB of data, call minute, or text message is billed as international roaming usage.
In short, your carrier “borrows” a local network for you – and bills you at a premium for it.
III. How much does data roaming cost in Vietnam?
Roaming prices depend on your home carrier and whether you have a roaming plan.
Below is the table listing data roaming costs of common network carriers in the world for using in Vietnam:
| Region/Country | Carrier | Pay-Per-Use Rate | Roaming Plan Option | Notes |
| USA | AT&T | $2.05/MB | $12/day (International Day Pass) | Day pass gives you regular plan data |
| USA | T-Mobile | Varies | Included on some plans | Unlimited but throttled to 2G speeds (128 kbps) |
| USA | Verizon | $2.05/MB | $12/day (TravelPass) | TravelPass gives you regular plan data |
| Europe | Vodafone | Premium rates | €6/day (Roaming Extra) | Varies by specific carrier |
| Europe | Most EU carriers | High rates | €5-15/day | Vietnam often excluded from standard EU roaming |
| Australia | Telstra | $5-10 AUD/MB | $10 AUD/day (Travel Pass) | Massive per-MB costs without pass |
| Australia | Optus | $5-10 AUD/MB | $10-15 AUD/day | Similar to Telstra pricing |
| Singapore | Singtel | High rates | $8-15 SGD/day | Better rates for nearby countries |
| Japan | NTT Docomo | High rates | ¥1,980-2,980/day | Approximately $13-20 USD per day |
| South Korea | Most carriers | High rates | ₩9,900-15,000/day | Approximately $7-11 USD per day |
To put the cost in perspective, below is a table that describes what these costs mean in real usage without a roaming plan:
| Activity | Approximate Data Usage | Cost at $10-15/MB |
| Streaming one YouTube video (10 min) | 50-100 MB | $50-150 |
| Checking email for 30 minutes | 20-50 MB | $200-750 |
| Scrolling social media (30 min) | 30-80 MB | $300-1,200 |
| Using Google Maps navigation (1 hour) | 5-20 MB | $50-300 |
| Video call (15 minutes) | 50-150 MB | $500-2,250 |
| One typical day of casual use | 200-500 MB | $2,000-7,500 |
Even with daily passes at $10-15 per day, a week-long trip costs $70-105 for roaming.
IV. When You Should Turn ON Data Roaming in Vietnam
In most situations, data roaming is best left off – but there are a few exceptions:
- You already bought an international roaming plan from your carrier that covers Vietnam.
- You’re on a short layover or business trip and only need data for a few hours.
- You’re in an emergency scenario and need your main number active.
- Your company pays for your international data expenses.
If you fall into these categories, check with your carrier before departure for an affordable roaming package.
V. When You Should Keep Data Roaming OFF in Vietnam
You should keep roaming disabled in nearly all other cases, especially if:
- You stay in Vietnam for more than a few days.
- You haven’t checked your carrier’s Vietnam rates. It’s safer to keep roaming off until you confirm.
- You are budget-conscious travelers.
- You’ve already set up a Vietnam eSIM for local data
- You’re traveling with family or a group – roaming costs multiply quickly (e.g., 4 people × $12/day = $336/week).
- You prefer to use free Wi-Fi or local data options.
Note that leaving data roaming on by mistake can quickly drain your credit or result in unwanted charges.
VI. How to Turn Off Data Roaming on Your Phone
On iPhone:
- Open Settings > Cellular > Cellular Data Options
- Toggle Data Roaming off
On Android:
- Go to Settings > Network & Internet > SIMs
- Tap your SIM and turn Data Roaming off
If you use dual SIMs (a home SIM and a Vietnam eSIM), make sure only your local eSIM is set for mobile data.
VII. What to Do If You Accidentally Left Roaming On
- Turn it off immediately once you notice it
- Check your carrier’s app or account for data usage
- Contact customer service and explain the situation — some carriers may offer a one-time adjustment
- Switch to a local eSIM plan for the rest of your trip
VIII. Better Alternatives to Data Roaming in Vietnam
Instead of paying premium roaming rates, you have several much better options for staying connected in Vietnam.
1. Vietnam eSIM Plans
Vietnam eSIMs — such as those from Vietnamesim.com — are the easiest and most budget-friendly option for tourists. You can install your eSIM before arrival, activate it once you land, and instantly enjoy fast local data without worrying about roaming charges.
For example, the Viettel eSIM offered by Vietnamesim.com connects to Viettel, Vietnam’s top mobile network. Plans start from:
- 5GB per day for 15 days – $13.9
- 5GB per day for 30 days – $19.9
There are also eSIM plans with data + calls + SMS offered by Vinaphone and MobiFone carriers – two other big Vietnamese network carriers – on Vietnamesim’s store. This gives you strong nationwide coverage and excellent value for your trip.
2. Local SIM Cards
You can also buy physical SIM cards at airports, mobile shops, or convenience stores. However, you’ll need to register with your passport as required by local regulations. This option works well if your device isn’t eSIM-compatible or if you prefer a physical SIM for backup.
3. Free Wi-Fi
Free Wi-Fi is widely available in hotels, cafes, airports, and shopping centers across Vietnam. It’s a good solution for light internet users who only need occasional access. However, keep in mind that public Wi-Fi may not be secure for sensitive transactions or personal data.