An eSIM for backpacking Southeast Asia: one country at a time, all on one phone

One pack per country, all on the same phone

Snoozim has a pack for each country on the usual routes: Thailand, Vietnam, Cambodia, Laos, Malaysia, Singapore, Indonesia and the Philippines. There is no regional Asia pack: each eSIM only carries data in its own country.

That is less work than it sounds. Most recent phones can keep several eSIMs installed, and Apple says an iPhone can hold eight or more, using one of them for data at a time. You install them all at home and move from one to the next at each border.

When each eSIM starts counting

Installing an eSIM does not start its plan. Each one starts counting at its first connection in its own country, so the Vietnam eSIM can sit untouched on the phone while you spend three weeks in Thailand. You can buy each pack up to 180 days before the trip.

Once a plan has started, its days run from that first connection. If your route leaves a country and comes back later, as it often does with Thailand, check how many days the first pack has left before you count on it for the return.

What to do at each border

• Before you cross, download offline maps of the next stretch and save your bookings, in case the switch takes a few minutes.
• Once across, switch on the eSIM for the new country and choose it as the line for mobile data.
• Check that data roaming is on for that eSIM; a travel eSIM needs it to connect.
• Leave the previous eSIM installed: you may need it on the way back, and top-ups go to the same eSIM.

The dual SIM setup guide shows where these settings are on iPhone and Android.

Bangkok, Chiang Mai and over the border to Laos

This is the classic start of the banana pancake trail, the loose backpacker loop through Thailand, Laos, Vietnam and Cambodia. The Thailand pack covers Bangkok, the islands and the north. From Chiang Khong, in the far north, you cross the Friendship Bridge to Huay Xai in Laos, and from there the slow boat takes two days down the Mekong to Luang Prabang, with a night in Pakbeng. The Laos pack takes over at the bridge. Much of the river is remote, so download maps and anything else you need before you board.

The other way into Laos is the overnight train from Bangkok to Vientiane, which crosses the Mekong on the first Thai-Lao Friendship Bridge. Passports are checked at Nong Khai and again at Khamsavath station in Vientiane; switch to the Laos eSIM once you are through.

Vietnam north to south, then Cambodia

Many people cross Vietnam from Hanoi to Ho Chi Minh City, or the other way round, in three or four weeks, which fits the 10 GB or 20 GB Vietnam pack, both valid for 30 days. From Ho Chi Minh City, buses run to Phnom Penh through the Moc Bai and Bavet border, the main land crossing on that road, and the Cambodia pack starts there.

Before planning to go on from Cambodia to Thailand overland, check current travel advice: the land crossings between the two countries have been suspended at times. Flying from Phnom Penh or Siem Reap to Bangkok is the way round it. Check the latest advice before you plan that leg.

Singapore and Malaysia

Singapore and Johor Bahru are joined by the Causeway, which buses cross all day. Use the Singapore pack until you clear immigration and the Malaysia pack from Johor Bahru on to Kuala Lumpur, Penang or the Cameron Highlands. Close to the Causeway the phone can pick up a network from the other side; if data stops, check which line and which network it is using.

Indonesia and the Philippines

Most people reach both by plane, and both are archipelagos where you move between islands by boat or domestic flight. The whole trip inside each country runs on one pack: the Indonesia eSIM on Bali, Lombok or Java, the Philippines eSIM from Manila to Palawan or Cebu. Between islands and on boats the signal can come and go, and offline maps keep you on track.

How much data per country

• Up to two weeks in a country, with maps, messages and some social media: 3 GB, valid for 15 days.
• Two to four weeks, with photos and video calls home: 5 or 10 GB, valid for 30 days.
• Working online or sharing the connection with a laptop: 20 GB, valid for 30 days.

If you stay longer than 30 days in one country, or run out of data, top up the same eSIM without a new QR code. Hotspot is allowed. The data calculator works out the size from your habits.

Calls, SMS and WhatsApp

These are data-only eSIMs: no phone number, no calls and no SMS. WhatsApp and other apps that run on data keep working with your usual number; the WhatsApp guide explains how. If you need your usual line for bank codes by SMS, keep it on for that and switch off its data roaming.