Most trip admin happens at home, weeks in advance, on a laptop. Digital arrival cards broke that habit. Half of Southeast Asia now wants an online form submitted before you land — and most of those countries refuse to accept it more than 72 hours out, which is exactly when you're least likely to be sitting somewhere with a reliable connection. You fill it in from a guesthouse, an airport gate, or a hotel lobby three countries into the trip, and you land needing to show a QR code.

Who wants what, and when the window opens
| Destination | Form | Required? | When you can submit |
|---|---|---|---|
| Thailand | TDAC | Yes, all non-Thai nationals | Within 3 days of arrival, including arrival day |
| Malaysia | MDAC | Yes, most foreign travellers | Up to 3 days before arrival |
| Singapore | SG Arrival Card | Yes, nearly all arrivals | Within 3 days of arrival, including arrival day |
| Indonesia | All Indonesia arrival card | Yes, everyone arriving | Up to 3 days before, or on arrival |
| Japan | Visit Japan Web | Optional | Any time before you fly |
A few notes worth having:
- Thailand retired the paper TM6 card on 1 May 2025 and replaced it with the Thailand Digital Arrival Card. It applies to arrivals by air, land and sea, children included. Transit passengers who never clear immigration don't need one.
- Malaysia's MDAC has applied to foreign travellers since 1 January 2024, with a list of exemptions — Singapore citizens and certain border-pass holders among them.
- Singapore abolished the paper disembarkation card back in 2020; the SG Arrival Card is the only version there is.
- Indonesia merged its customs and health declarations into a single All Indonesia arrival card in October 2025, so it's one form and one QR code instead of three.
- Japan's Visit Japan Web is genuinely optional — paper forms are still handed out and still accepted — but registering ahead gives you one QR code for immigration and customs, which is the difference between a fast lane and a slow one.
All of them are free on the destination's own official portal. Singapore's immigration authority goes out of its way to say it doesn't endorse the commercial sites that charge a "service fee" for submitting a form you can file yourself in five minutes. Rules also change faster than blog posts do, so check the official site for your destination before you travel.

Why a 72-hour window is a travel problem
On a single round trip it's trivial: you're at home, you fill the form in, done. On any real itinerary it isn't.
Fly into Bangkok, spend ten days moving north, then hop to Kuala Lumpur and on to Singapore, and each of those forms becomes something you complete mid-trip — from a sleeper train, a ferry terminal, or a hotel with Wi-Fi that drops every time someone uses the lift. The window opens while you're already travelling, and it closes at the moment of arrival.
That's a connectivity problem dressed up as a paperwork problem. The forms themselves are short: passport details, flight number, where you're staying. What they need is a connection you can rely on for ten uninterrupted minutes, at a time and place you can't pick.
Which is why the pre-trip setup matters more than it seems. Install a VamosData eSIM for each leg before you leave, and the form is something you fill in from the departure gate on your own data instead of negotiating with a captive portal. If you're only crossing one border, a single-country plan does it; for a multi-country run through the region, a regional plan saves juggling. Both live on destinations.
What you actually have to show on arrival
A QR code, in almost every case — emailed to you, or shown in the portal or app. Officers scan it, and some airports have kiosks that pair it with your passport.
Three habits make that reliably painless:
- Screenshot the QR code the moment you get it, and keep the email too. Screenshots survive dead batteries less well than paper, but they survive a bad signal at the immigration hall, which is the realistic failure.
- Check the details before you submit. Passport number, full name, date of birth and nationality are typically the fields you can't edit afterwards — you'd have to file again.
- Have working data anyway. Flights get rerouted, addresses change, and the fix is usually resubmitting the form from the arrivals hall. With your VamosData eSIM already live, you do that standing in the queue; without it you're looking for a Wi-Fi code you can't receive.
The pre-arrival routine
- Confirm your phone supports eSIM with the device checker, and install your VamosData eSIM at home (iOS / Android).
- Set a reminder for each arrival card 48 hours before that leg — inside the window, with a day of slack.
- Submit on the official portal, screenshot the QR code, and file it somewhere you can find offline.
- On landing, turn data roaming on for your VamosData line and leave your home line's roaming off — the full routine is in your first 30 minutes in a new country.
None of this is hard. It's just moved: the form that used to be a scrap of cardboard and a borrowed pen on the plane is now a thing you do three days out, on the internet, wherever you happen to be standing.