Quick answer
Install this eSIM on Wi-Fi before a flight to Changi (SIN), or on Wi-Fi after you land. Installing the day before the flight uses no days, and days start when the eSIM first connects to a network. Turn on Data Roaming for this eSIM at no extra charge. A layover uses a 1-day plan: 500 MB/day or Unlimited.
Should I buy a SIM at the airport or use an eSIM?
This eSIM is data you install from a QR in your email. You do not upload documents, and you do not need a local phone number for maps, Grab, or WhatsApp. WhatsApp calls work over this data.
Keep Data Roaming off on your home SIM. The same eSIM also works in Malaysia.
When should I install the eSIM?
Install it on Wi-Fi, the day before you fly or when you have Wi-Fi after you land. Installing the day before the flight uses no days. Days start when the eSIM first connects to a network. Pick one day more than the stay. The QR arrives by email, stays on your order page, is valid for 30 days, and scans once.
- 1Scan the QR on Wi-Fi and label the new line “Singapore”.
- 2On landing, turn off airplane mode.
- 3Turn on Data Roaming for the Singapore line, and choose it for mobile data.
- 4Keep Data Roaming off on your home SIM.
- 5Open a map or Grab before you leave, so you know the eSIM is working.
Which plan suits Changi?
A layover uses a 1-day plan: 500 MB/day or Unlimited. Unlimited has no data cap listed. An overnight stop uses 3 days · 3 GB. Hotspot is included. There are no top-ups.
What if I have not installed the eSIM yet?
You need Wi-Fi to install. Open the email or your order page, scan the QR from a second screen, or type the manual install code under the QR. Then turn on Data Roaming for the Singapore line and pick it for mobile data. The APN is mobile.three.com.hk. That string is the APN only.
Frequently asked questions
Do I need Data Roaming on at Changi?
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Yes, for this eSIM. It is a 4G roaming eSIM, and there is no extra charge. Keep Data Roaming off on your home SIM.
Does Grab work on this eSIM?
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Grab is ride-hailing you can use over this data. TikTok and most AI apps, such as ChatGPT, may not work on this eSIM.
Which plan suits a layover?
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A 1-day plan: 500 MB/day or Unlimited. Days start when the eSIM first connects to a network. Installing the day before the flight uses no days. Pick one day more than the stay.
Related guides
Singapore trip checklist: eSIM before you fly
What to sort out before you fly.
How to install a Singapore eSIM on iPhone
Scan the QR, label the line, and turn on Data Roaming.
Singapore eSIM not working? Fixes for no data after landing
Checks to run in the arrivals hall.
Marina Bay eSIM guide: maps, Grab, and WhatsApp
Marina Bay, on this Singapore eSIM.