eSIM for Southeast Asia: What One Plan Actually Covers
The short answer
The Asia+ regional eSIM covers six Southeast Asian countries on one install: Thailand, Vietnam, Malaysia, Singapore, Indonesia and the Philippines. It does not cover Cambodia, Laos or Myanmar. If your route includes those, you add a country plan for that leg — they are sold separately and install alongside the regional one. Plans start at €3.46 for 5 days and 1 GB, and a 30-day 20 GB plan is €29.50.
That distinction matters more here than almost anywhere else, because the single most popular route through this region — Bangkok, overland to Siem Reap, on to Phnom Penh, across to Vietnam, out through Laos — crosses two countries the regional plan does not include. Most comparison articles will not tell you that. Check the country list against your actual itinerary before you buy anything.
Photo by Quang Nguyen Vinh on Pexels
What the regional plan covers
In Southeast Asia:
- Thailand
- Vietnam
- Malaysia
- Singapore
- Indonesia
- Philippines
The same plan also covers Japan, South Korea, Taiwan, Hong Kong, China, Australia and New Zealand — thirteen countries in total — so a trip that continues up to Tokyo or down to Sydney stays on one plan.
What it does not cover
Cambodia, Laos and Myanmar are not on the regional plan. Nor are India, Nepal, Sri Lanka, Bangladesh, Mongolia, Macau or the Maldives. Cambodia and Laos are both available as individual country plans, which is the straightforward fix for a route that dips into them.
How to cover the classic overland loop
The Bangkok–Siem Reap–Phnom Penh–Ho Chi Minh City–Hanoi–Luang Prabang circuit needs two purchases, not one:
| Leg | Covered by |
|---|---|
| Thailand — Bangkok, the islands, Chiang Mai | Regional plan |
| Cambodia — Siem Reap, Phnom Penh | Cambodia country plan |
| Vietnam — Ho Chi Minh City to Hanoi | Regional plan |
| Laos — Luang Prabang, Vientiane | Laos country plan |
| Malaysia and Singapore — the southern run | Regional plan |
Both can sit on the phone at once. You enable whichever line matches the country you are in, which takes a few seconds in your settings. It is less elegant than one plan for everything, but it is the honest answer, and it is cheaper than paying roaming rates for two countries.
Why any of this matters — there is no ASEAN roaming
There is no regional roaming agreement between Southeast Asian countries comparable to the EU's. A Thai SIM used in Vietnam is charged at full international roaming rates, and those rates are high. Nothing you buy in Bangkok helps you in Hanoi. This is the single biggest practical difference from travelling around Europe, and it is why the plan you choose matters more here.
It bites hardest at land borders. Crossings like the Johor–Singapore causeway involve long outdoor queues where you may need a booking reference, an e-visa confirmation, or a call to an onward driver — and a country SIM stops working the moment you leave its territory. A regional line stays connected through the crossing because it is not tied to one country's network.
How much data you actually need
| Trip style | Typical daily use | Two weeks | One month |
|---|---|---|---|
| Light — maps, messaging, occasional lookup | 150–250 MB | 3 GB | 5 GB |
| Normal — the above plus ride-hailing, translation, social | 400–600 MB | 5–10 GB | 10–20 GB |
| Heavy — video calls home, uploading photos and clips daily | 1 GB+ | 20 GB | Unlimited |
Two things push usage above what the same trip length would cost you in Europe. Ride-hailing apps run GPS continuously and get used several times a day rather than occasionally. And accommodation Wi-Fi is unreliable enough that people give up and tether, which quietly moves laptop traffic onto the mobile plan.
What it costs
| Duration | 1 GB | 5 GB | 10 GB | 20 GB | Unlimited |
|---|---|---|---|---|---|
| 5 days | €3.46 | €8.67 | €14.74 | €24.29 | €16.48 |
| 10 days | €4.33 | €9.54 | €16.48 | €26.89 | €27.76 |
| 15 days | €5.20 | €10.40 | €17.35 | €28.63 | €39.04 |
| 30 days | €6.93 | €10.40 | €17.35 | €29.50 | €73.75 |
Worth noticing: at 5 days the unlimited plan (€16.48) costs less than 20 GB (€24.29), so on a short heavy-use trip unlimited is simply the better buy. At 30 days that inverts sharply — €73.75 against €29.50 for 20 GB — so on a long trip take a capped plan unless you genuinely intend to tether a laptop daily. Prices refresh regularly; the plan page always shows the current figure.
Coverage quality across the covered countries
Coverage is strong and genuinely fast where you will spend most of your time. Bangkok, Ho Chi Minh City, Hanoi, Kuala Lumpur, Singapore, Jakarta and Manila all have dense 4G with 5G in central districts. Singapore and Malaysia are the best of the six; Vietnam's urban coverage is excellent and inexpensive by any standard.
Expect it to thin out in predictable places: the Thai islands once you are away from the main beaches, the Mekong Delta's smaller channels, the Philippine islands beyond Luzon and Cebu, and inland Indonesia away from Java and the Bali tourist zones. The practical response is the same everywhere — download offline maps for the next stop while you are still on hotel Wi-Fi.
Routes that work on one plan
The southern run, 10 days
Bangkok → Kuala Lumpur → Singapore, by train and bus down the peninsula. Three countries, all on the regional plan, excellent coverage the whole way. The Johor–Singapore causeway is the one border where you will really want working data in the queue.
Thailand and Vietnam, 2–3 weeks
Bangkok → Chiang Mai → Ho Chi Minh City → Hoi An → Hanoi. Two countries by domestic flights and trains, entirely on the regional plan. A 15-day 10 GB plan at €17.35 is the usual fit.
Islands, 3 weeks
Manila → Cebu → Singapore → Bali. Three countries plus a lot of inter-island hops. Ferry timetables in the Philippines change often and are checked online, so data here is a necessity rather than a convenience.
Getting set up
Install before you fly. The eSIM arrives by email as a QR code within about thirty seconds of payment, and scanning it needs a working internet connection — precisely what you will not have in the arrivals hall. Install at home on Wi-Fi, leave the line switched off, and enable it when you land.
You will need an eSIM-capable phone: iPhone XS or newer, or most Android handsets from the last few years. One caveat specific to this region — phones bought in some Southeast Asian markets are carrier-locked more often than European models, so if you are travelling on a handset bought locally, check it is unlocked first.
FAQs — Southeast Asia eSIM
Does the regional plan cover Cambodia?
No. Cambodia is not on the Asia+ regional plan. It is available as a separate country plan, which you can install alongside the regional one and switch on for the Cambodian leg of your trip.
Does it cover Laos?
No. Laos is not on the regional plan either, and it too is sold as a separate country plan. If your route is the classic Thailand–Cambodia–Vietnam–Laos loop, you will need the regional plan plus two country plans to stay connected throughout.
Which Southeast Asian countries are on the regional plan?
Thailand, Vietnam, Malaysia, Singapore, Indonesia and the Philippines. Beyond Southeast Asia it also covers Japan, South Korea, Taiwan, Hong Kong, China, Australia and New Zealand — thirteen in total.
Is there anything like EU roaming in Southeast Asia?
No. There is no regional roaming agreement between ASEAN countries comparable to the EU's. A Thai SIM in Vietnam is charged at full international roaming rates, and those rates are high. This is why the plan you choose matters more here than on a Eurotrip.
Can I have the regional plan and a country plan on the phone at once?
Yes. Modern handsets hold several eSIM profiles and let you enable whichever you need. You keep both installed and switch the active line when you cross into Cambodia or Laos — a few seconds in your settings, no reinstalling.
How much data do I need for a month of backpacking?
For most people, 10–20 GB over 30 days. Light users navigating and messaging get by on 5 GB. If you are video-calling home regularly or uploading footage, take 20 GB or unlimited. The two things that blow budgets on this route are ride-hailing, which runs GPS continuously, and tethering a laptop when hostel Wi-Fi fails.
Can I keep my home number for banking codes while using the eSIM for data?
Yes. The eSIM is a second line. Your physical SIM stays in the phone with its data switched off, so it can still receive SMS verification codes from your bank, while all data runs over the travel eSIM. This avoids the classic problem of being locked out of a banking app in a country where you cannot receive a text.
Can I top up if I run out halfway through Vietnam?
Yes. A top-up applies to the eSIM already installed on your phone — you do not reinstall, rescan, or lose your remaining days. It takes effect within a minute or two.
Does unused data carry over when I cross into the next country?
Yes, within the regional plan. The allowance is pooled across all thirteen countries for the whole duration rather than split per country, so a light week in Malaysia leaves more for Vietnam. A separate country plan has its own allowance.
Which devices support eSIM?
iPhone XS, XR and newer, Google Pixel 3 and newer, and most recent Samsung Galaxy S and Note models, along with a wide range of other recent Android handsets. The phone must also be carrier-unlocked. If you are unsure, dial *#06# — if the display includes an EID alongside the IMEI, the handset supports eSIM.
How do I check which countries are included before I buy?
The full country list is on the plan page itself, so you can confirm your exact itinerary is covered before paying rather than afterwards. Given that Cambodia, Laos and Myanmar sit outside the regional plan, this is worth two minutes before you travel.
Country guides for this route
- Thailand eSIM guide
- Vietnam eSIM guide
- Malaysia eSIM guide
- Singapore eSIM guide
- Indonesia eSIM guide
- Philippines eSIM guide
- Cambodia eSIM guide — separate country plan
- Laos eSIM plans — separate country plan
Or see the wider Asia eSIM guide if your trip goes beyond Southeast Asia.
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