What to do when your Vietnam eSIM runs out of data

Most Vietnam eSIM plans — especially those designed for tourists — use a daily data allowance rather than a single total cap. For example, a '5GB/day for 7 days' plan gives you 5GB each calendar day (or rolling 24-hour period, depending on the carrier). When you hit that daily limit, your speed is either throttled to a very slow 3G/Edge connection or cut entirely. No automatic top-up kicks in; you simply wait until the next day (for the allowance to reset) or buy a new plan.

Some plans, like certain Mobifone offerings, use a total data cap — e.g., 7GB total over 7 days — but these are less common for tourist eSIMs. Most of the plans we offer are daily-refresh models. The plan also has a fixed duration (7, 10, 15, or 30 days). After the last day, the plan expires and no data is available, even if you haven't used all the daily data on the final day. So step one: check whether you've hit the daily cap or the plan has expired. On iPhone, go to Settings > Cellular > tap your eSIM to see current period usage. On Android, check the SIM settings for data warning or usage.

The quickest way to get back online is to purchase a new eSIM. Our eSIMs are pre-loaded fixed plans — we do not offer top-up or refill. Once your data is exhausted or the plan expires, you simply buy a new one and activate it. This can be done from the same phone in under two minutes: you receive a QR code by email, scan it, and install the profile. The new eSIM can be installed while the old one remains on your phone (until you remove it) — though you'll need to set the new line as the data line in your cellular settings.

Some carriers like Viettel and Vinaphone allow direct top-up on their customer portals, but that requires your SIM to be registered under a Vietnamese ID — which tourist eSIMs sold through resellers are not. So for travelers, the easiest route is a fresh eSIM. We recommend a short-term plan like Mobifone 7GB/day for 7 days ($8) or Viettel 5GB/day for 7 days ($9.9). Both are cheap, fast, and work immediately. If you have a dual-SIM phone, you can keep the old eSIM for receiving incoming SMS (if it's a Vinaphone plan with a Vietnamese number) while using the new plan for data.

If you'd rather not spend money on a new eSIM right away, or if you're in a spot with free Wi-Fi, you can get by for a while without mobile data. Vietnam has excellent Wi-Fi coverage in cafes, hotels, restaurants, and shopping malls — many places offer free Wi-Fi with decent speeds. You can use hotel Wi-Fi to install a new eSIM (e.g., from simvietnam.telebox.vn) or message your accommodation host for directions.

Before you lose data entirely, download offline maps for Hanoi, Ho Chi Minh City, and Da Nang using Google Maps or Maps.me. These let you navigate without an internet connection. For urgent needs like booking a Grab ride, ask nearby staff for the Wi-Fi password — many cafes print it on the receipt. Wi-Fi calling (if your home carrier supports it) can also work over a Wi-Fi connection, but it requires initial setup beforehand.

To avoid running into this issue on your next trip, turn on data usage alerts. On iPhone: Settings > Cellular > Current Period — reset it manually at the start of each day. On Android: set a data warning in SIM settings (e.g., 4.5GB if your plan is 5GB/day). This way you'll get a notification before you hit the cap.

Monitor which apps consume the most data. Video streaming, social media autoplay, and navigation in real-time can eat through your daily allowance quickly. Whenever possible, use Wi-Fi for heavy tasks like uploading photos, video calls, or downloading podcasts. If you're traveling longer than 10 days, consider a 30-day plan (like Viettel 5GB/day for 30 days at $18.9) so you don't have to worry about daily or total caps.

Our plans are based on calendar days from the moment you activate them. For example, a 7-day plan is valid for 168 consecutive hours. If you activate it too early — say at midnight on Day 0 — it may expire before your departure date. To maximize coverage, activate a long plan on the morning after you arrive, not the moment you land. If you're staying 15 days, a 15-day plan activated on Day 1 will last the whole trip.

If the plan expires before your trip ends, simply buy a new short-term plan covering the remaining days. You can install a new eSIM while the old expired profile remains on your phone (to free up a slot later). For overlapping plans, if you have a dual-SIM phone, you can assign one line for data and the other for SMS (if the old plan had a number) — just remember the new plan will be data-only unless it's a Vinaphone plan with a Vietnamese number.

If your plan expires early due to incorrect activation timing, the solution is straightforward: buy a new eSIM for the remaining days. We recommend not activating a long plan the moment you arrive; instead, activate it the next morning to align with your travel schedule. Example: 15-day trip — activate a 15-day plan on Day 1; if you activate on Day 0 (midnight), you effectively lose a day of coverage.

If you need emergency data for just a day or two, consider a 7-day plan and activate it for the last leg. The new eSIM will work independently of the old one. On a dual-SIM phone, you can keep both profiles active — just set the new line as the data line. Label each profile clearly in your phone's settings to avoid confusion later.