The Asia label does not prove Vietnam is included
This is the single most expensive mistake in this comparison. Regional eSIMs are grouped under names like Asia, Southeast Asia or Asia-Pacific, and those names describe different destination lists. On VietSIM, the four-country regional family covers Singapore, Malaysia, Indonesia and Thailand. Vietnam sits in a different, broader Asia-Pacific family with its own destination list, which also includes the Philippines.
So a plan labelled Asia can be sold to you with a Thailand flag on the card and still not carry Vietnam. Before you pay, open the plan details and read the included destinations line by line. If Vietnam is not named there, the plan will not work in Vietnam, whatever the product image suggests.
Check both countries by SKU, not by category
A SKU is the specific product you actually buy. Two plans in the same category can have different destination lists, different networks and different installation rules. Check these fields on each candidate plan:
- Included destinations — is Vietnam named, and is Thailand named?
- Network — which carrier does the plan attach to in each country?
- Data and validity — a total allowance with a fixed window, or a daily allowance?
- Validity trigger — does the clock start at installation, at first connection, or on arrival?
- Installation rule — some local plans must be installed in the country, not before departure.
- Local number — included or data-only?
- Hotspot — permitted, and does tethering draw from the same allowance?
That last set of fields is where the two-country decision actually gets made. VietSIM's Thailand page is explicit that the local dtac family it selects requires installation in Thailand, so a generic "install before you fly" instruction will send you wrong. Vietnam plans do not carry that same warning.
A 7 plus 7 day comparison
The table below uses the plan families currently listed on the VietSIM store pages (retrieved 2026-10-16). Prices and availability move, so treat these as the shape of the decision rather than a permanent quote.
| Option | What it covers | Data shape | Local number | Best for |
|---|---|---|---|---|
| Vietnam local plan (7 days) | Vietnam only | 15 GB total, or 7 GB per day on some SKUs | Some SKUs include a Vietnamese number | The Vietnam leg |
| Thailand local plan (7–10 days) | Thailand only | 15 GB total, 50 GB total, or unlimited on some SKUs | Local number included on the listed options | The Thailand leg |
| Regional Asia plan | Named destinations only — check the list | One shared allowance, one shared window | Data only on the listed options | Itineraries where the regional list genuinely matches every stop |
Two country plans give you two allowances and two clocks. A regional plan gives you one of each. On a 14-day trip that difference is the whole argument: a shared 3 GB regional allowance does not reset when you land in Bangkok, and neither does the validity window.
Local number and hotspot trade-offs
The listed Thailand local options include a local number. The Vietnam options vary — some carry a Vietnamese number, some are data-only. If you need to receive calls, register for a local app or give a number to a hotel or driver, that field decides the purchase, not the price.
Hotspot behaviour also differs by SKU. Tethering draws from the same allowance on a data-only plan, so a laptop session can eat a day's data quickly. If you plan to work from a cafe or share a connection with a travel companion, size the allowance for two devices, not one. Our guide to using a Vietnam eSIM as a hotspot covers the tethering rules and how much data it actually consumes.
Switch data lines on arrival
Running two eSIMs on one phone is normal, and it is how most travellers handle a two-country trip. Install both before you fly where the plan allows it, keep your home SIM active for SMS and bank codes, and set only one line to carry mobile data at a time.
When you cross from Vietnam into Thailand, change the default data line in your phone settings. The Vietnam plan stops being used, the Thailand plan starts, and your home number stays reachable for verification texts. If you have not done this before, our explainer on dual-SIM setup for Vietnam walks through the line settings. The same logic applies in reverse on the way home.
Choose by itinerary, not by the word Asia
Work backwards from your actual route:
- Vietnam only, then home. One Vietnam plan. Nothing else to decide.
- Vietnam then Thailand, or Thailand then Vietnam. Two country plans, unless a regional plan names both countries and the shared allowance genuinely covers your total usage.
- Vietnam, Thailand and a third stop. Check the regional destination list first. If it names all three, the regional plan may win on convenience. If it names two of three, buy the country plan for the odd one out.
- A long Vietnam stay with a short Thailand hop. Buy a longer Vietnam plan and a short Thailand plan. Do not stretch a regional allowance across a month.
If your route also includes Cambodia, the same logic applies with a different set of plans — see Vietnam and Cambodia eSIMs: one plan or two.
What to buy for this trip
For a Vietnam-and-Thailand itinerary, buy the Vietnam eSIM for the Vietnam leg and the Thailand eSIM for the Thailand leg. Match each plan's length to the days you actually spend in that country, and pick a local-number SKU if you need calls or app registrations.
Only choose a regional Asia eSIM if its included destinations list names every country on your route and the shared data allowance covers your total usage across the whole trip. Read that list before you pay — the word Asia is not a guarantee.
If you are still deciding how much data you need, our guide to tracking your Vietnam mobile data shows what a normal travel day consumes. And if you have already bought and lost the email, the help centre is the route back to your order — there is no public order lookup page.