The four options
| Option | Pros | Cons |
|---|---|---|
| eSIM | Buy and install before you go, works on arrival, your own SIM stays in the phone | Needs an eSIM-capable, unlocked phone; most plans are data-only with no local number |
| Local SIM | Often cheapest, with a local number for calls | Bought after you land, and many countries require your passport to register it |
| Roaming | Nothing to do, your number stays the same | Usually the most expensive without a special travel plan |
| Pocket Wi-Fi | One device for several people and devices | Another gadget to charge and carry, and the group depends on it |
How an eSIM works
An eSIM is a digital SIM built into your phone. You buy a plan on a website or app and receive a QR code, which you scan in your phone's settings to install it. Install it at home on Wi-Fi, then switch it on when you land, from the same settings.
- Check your phone supports eSIM: most recent phones do; look in the network or SIM settings.
- Check your phone is unlocked: a phone locked to a carrier won't accept another provider's SIM.
- Choose the plan for how you'll use it: maps and messages use little data; video calls and uploading photos use a lot.
Your home number and bank texts
Bank verification codes and some apps are sent to your home number. If you use an eSIM, keep your original SIM switched on to receive texts, with data roaming turned off on it. Receiving texts abroad is free or cheap with many providers, but check with yours.
How to avoid a surprise roaming bill
- Turn off data roaming on your home SIM before take-off, unless you've bought a roaming plan.
- Watch out for automatic photo backups and updates: they can use up a whole plan in a day.
- Download maps, films and playlists before you go.
- Call family through internet apps rather than ordinary international calls.
Public Wi-Fi
Wi-Fi in hotels, cafés and airports is useful but not always secure. Don't log in to your bank or pay over an open public network; use your phone's data for that.
Our advice: on our Thailand trips, a local SIM card is included in the package. For other destinations, we tell you the best internet option before you go.