Southeast Asia eSIM

Southeast Asia is a region where the local carrier matters more than the price. Each plan here runs on a major domestic network rather than a regional roaming profile, which is why they hold up on Phu Quoc, in Bali and in the Malaysian interior. Two plans cross borders on purpose: the Singapore eSIM also works in Malaysia and the Malaysia eSIM also works in Singapore — useful if you are doing the Causeway run.

Which Southeast Asia eSIM should you choose?

How to choose, plan comparison and FAQs (tap to open)

Pick by country first, then by data style. Thailand runs on Dtac and is the one plan with a hard rule attached: install it only after you land. Scanning the QR code before you arrive in Thailand invalidates the profile, and that is the single most common support ticket we see for this destination. Vietnam uses Viettel, which has the widest reach in the country including Phu Quoc, and comes as a flat 5GB per day across 3 to 15 days rather than a menu of tiers.

Destination	Network	Plan styles	Trip length	Worth knowing
Thailand	Dtac	15GB high-speed, 50GB high-speed, or unlimited	5–10 days	Install only after you arrive in Thailand. Unlimited is not throttled.
Vietnam	Viettel	5GB per day	3–15 days	Widest coverage in the country, Phu Quoc included. Install within 15 days of purchase.
Singapore	Singtel	5/10/20GB total, 1/2/3GB per day, or unlimited	3–30 days	Also works in Malaysia.
Malaysia	Top-three domestic carrier	5/10/20GB total, 1/2/3GB per day, or unlimited	3–30 days	Also works in Singapore.
Indonesia / Bali	Telkomsel	5/10/20GB total, 1/2/3GB per day, or unlimited	3–30 days	Strongest option for Bali and the outer islands.
India	Leading domestic 4G/5G network	1/2GB per day, or 10/20GB total	1–30 days	Covers Delhi, Mumbai, Bengaluru and interstate travel.

Pricing and the exact day/data combinations available are shown on each product page.

Frequently asked questions

Why must the Thailand eSIM be installed after arrival?

The Dtac profile registers against the local network on activation. If you scan the QR code while still outside Thailand the profile is consumed and will not work. Wait until you land — airport Wi-Fi at BKK, DMK, CNX and HKT is free and enough to complete the install.

Does one eSIM cover the whole of Southeast Asia?

Not these ones. Each is a domestic carrier plan for a single country, which is what keeps the signal strong outside the capitals. The exceptions are Singapore and Malaysia, which each work in the other country.

Will the Indonesia eSIM work properly in Bali?

Yes. It runs on Telkomsel, which has the broadest coverage in Indonesia, and that includes Bali beyond the main tourist strips as well as Java and the other islands.

Does the Vietnam eSIM work on Phu Quoc?

Yes. Viettel is the largest carrier in Vietnam and reaches Phu Quoc along with Hanoi, Da Nang, Hoi An and Ho Chi Minh City. Note that this plan must be installed within 15 days of purchase, so do not buy it months ahead.

How much data do I need for a week in Southeast Asia?

Do not take the smallest tier. Maps, ride-hailing apps, messaging, translation and social media add up to more than travellers expect, so around 3GB a day is a safer target — and most destinations here also offer 5/10/20GB total-data plans, usually our first recommendation because a heavy day will not leave you stuck. Choose unlimited if you stream video or work from your phone.