eSIM for Southeast Asia

The plan covers seven countries, Thailand, Vietnam, Indonesia, Singapore, Malaysia, the Philippines and Cambodia, which is the classic backpacker loop, and it does not cover Laos, Myanmar, Brunei or Timor Leste, the four countries most people assume come bundled with the word regional.

Laos is the one that hurts. The Thailand to Laos to Vietnam overland route is one of the most walked paths in the region, and this plan goes quiet the moment you clear the Friendship Bridge or step off the slow boat at Huay Xai. If Luang Prabang or Vang Vieng is on your list, plan for a local SIM there and treat those days as offline for this plan. Nobody else will tell you that before you pay.

The other reason coverage lists confuse people is that travellers think in places, not countries. Penang and Langkawi are Malaysia. Palawan and Cebu are the Philippines. Ha Long and Hoi An are Vietnam. Gili Trawangan is Indonesia. If the spot you are going to sits inside one of the seven, you are covered, and if you cannot work out which country a place belongs to, that is the question worth asking before you buy.

The entry price of $1.29 gets you the smallest plan on the shelf, and because our best rate on plans of 20GB or less works out at $1.40 a gigabyte, that $1.29 headline does not stretch to a full gigabyte of data. It is a one day plan, not a bargain hiding in plain sight.

This is the trick every brand plays, including us until now. A from price tells you how small the smallest plan is. It tells you nothing about the plan you will actually buy. Anyone hunting for the best eSIM for Southeast Asia should compare the cost per gigabyte across the sizes they would realistically use, then check what the big brands work out to on the same basis. Our best rate on plans of 20GB or less is $1.40 per gigabyte, and the 50 GB plan brings it down to $1.26. Hold everyone else to the same test.

There are 11 plans on Southeast Asia and none of them are unlimited. Not a throttled unlimited, not a fair use unlimited, none at all. If another page sells you unlimited for this region, go and find the daily cap in their terms, because there is always one.

No, because a travel eSIM roams on partner networks instead of issuing you a local number, so the registration rules that catch tourists buying local SIM cards in Vietnam and the Philippines do not reach you at all.

This matters more than it sounds. The Philippines runs a SIM Registration Act that asks visitors buying a local prepaid line for a passport, a local address such as your hotel, and sometimes proof of onward travel, with the registration valid for a limited window. Vietnamese airport counters want your passport before they hand over a SIM. A roaming eSIM skips both queues, and you land already connected rather than standing at a counter after a red eye flight.

Indonesia goes further. Buy a local Indonesian SIM or eSIM and your handset IMEI has to be registered before the phone will connect to anything. Indonesian customs guidance says inbound roamers using a foreign SIM do not need to register an IMEI, which is exactly what a travel eSIM makes you. That is one customs desk you can walk straight past in Denpasar.

You do not pick your network, the eSIM attaches to a partner in each country automatically, but it helps to know which ones travellers rate highly: AIS in Thailand, Telkomsel in Indonesia, and Viettel or Mobifone in Vietnam.

Those preferences are not random. Telkomsel is the one people report still moving once you leave the Canggu and Seminyak strip. AIS is the name that keeps coming up on the smaller Thai islands, where the other networks thin out fast. If your phone latches onto something slow after a border, open your mobile network settings, turn off automatic selection, pick a network by hand and see if it improves, then set it back to automatic a day later.

Be realistic about the edges. Towns, cities, main roads and islands with a ferry service are fine on any decent network. Mountain passes in northern Vietnam, jungle treks and the middle of a long boat ride are not, on any provider or any plan. Download offline maps for Ha Giang or the Thai hill country before you set off, and stop blaming the eSIM for physics.

Yes, WhatsApp and FaceTime calling work normally across Southeast Asia, which is worth stating because a lot of travellers arrive braced for a block after reading advice written for the Gulf, where VoIP calling really is restricted on local networks.

The layover is where that advice does apply. Plenty of cheap routes into the region connect through Doha or Dubai, and those are the airports where the call home gets awkward. This plan does not cover the Gulf either, so treat the stopover as airport wifi only and save the call for after you land in Bangkok.

One thing the plan genuinely will not do is give you a phone number. It is data only, so no SMS codes arrive on it. Set up Grab, Gojek and anything with a text message login while you are still at home on your normal number. Doing it after you land means switching roaming back on for your home line just to receive one code, and that is how people end up with a bill bigger than the eSIM.

Count the days you will genuinely be using mobile data rather than the length of the whole trip, because hostels, cafes and airports across the region give wifi away, and validity on this plan starts when the eSIM first connects to a network rather than on the day you pay for it.

With 11 sizes there is usually one close to your route, so the real choice is one long plan or a small one you top up. A single long plan is tidy and you pay for all of it upfront, including the fortnight you spend on a beach with hotel wifi. Buying small and adding more means you only pay for the weeks you actually move around. Neither is wrong, but pick deliberately instead of buying the biggest box on the shelf.

Then think about what you do with your phone. Maps, messaging and booking beds are light. Daily reel uploads from a boat, video calls home and streaming on a night bus are not. Before you fly, set iCloud or Google Photos to back up on wifi only, because a week of holiday photos syncing over mobile data will empty a small plan while you sleep.

Do not buy this plan if you are only visiting one country. A single country plan will give you more data for the money, and there is nothing the regional plan does inside Thailand that a Thailand plan does not do better. Do not buy it if Laos or Myanmar sits on your route, because you will be offline there and still paying. Do not buy it if you want unlimited data, since there is no unlimited option on this region at all and finding that out after you land is a bad afternoon. And if Singapore is just a six hour layover, use the free wifi at Changi and buy nothing.