Roaming on your home carrier is the most expensive way to use data abroad. A local SIM (or eSIM) at your destination is almost always cheaper for the same data — but it only works if your phone is unlocked.
Physical SIM or eSIM — either works, once unlocked
Most phones from the last several years support eSIM, which lets you add a destination carrier as a digital profile without swapping a physical card — handy if you want to keep your home SIM active for calls and texts while data runs on the local plan. Older phones, or trips where you want a physical backup, can use a local SIM card bought on arrival or in advance online.
This dual-SIM setup is worth calling out on its own: keeping your home number active on an eSIM means text-message two-factor codes and calls from home still reach you, while a cheap local SIM or eSIM handles data and any local calls — often the best of both without paying roaming rates for data.
- 1Unlock before you travelDo this at home, with a stable connection and time to sort out any issue — not at the airport. See the order box.
- 2Check band compatibilityMost modern phones support a wide range of bands, but it's worth a quick check for older or region-specific models before you rely on it.
- 3Get your local SIM or eSIMAt an airport kiosk, a local shop after landing, or an eSIM purchased online before you leave — whichever fits your itinerary.
- 4Insert or install it, then restartSome networks need an APN entered manually if it doesn't configure automatically — check the local carrier's instructions if data doesn't connect right away.
It's also worth confirming your phone is genuinely unlocked before you leave rather than assuming — see carrier-locked vs. unlocked phones for the quick Settings check. Finding out at the airport that a phone is still locked is a far more stressful moment than finding out at home with time to fix it.
| Option | Typical trade-off |
|---|---|
| Home carrier roaming | Simplest, usually the most expensive per GB |
| Local SIM bought on arrival | Cheapest data, but takes time at the airport or a local shop |
| Travel eSIM bought in advance | Set up before you land, no physical card to swap |
For the full list of what unlocking changes beyond travel, see the benefits of unlocking your phone. If you already have an unlocked phone and just want to confirm it, see carrier-locked vs. unlocked phones.
Buying a used phone specifically for travel
If you're buying a secondhand phone as a dedicated travel device, checking its IMEI first matters even more than usual — a blacklisted or still-locked phone bought for a trip is a problem you'll discover far from home. See checking a used phone's IMEI before you buy before you commit.
Will an unlocked phone work with any SIM, anywhere in the world?
Being unlocked removes the carrier restriction, but the phone's hardware still needs to support the local network's frequency bands — true for almost all recent phones, but worth a quick check for older or budget models.
Do I need to unlock my phone every time I travel?
No — an official unlock is a one-time, permanent change. Once it's done, you can use any local SIM on any future trip.
Should I unlock before I leave or can it wait until I land?
Unlock before you leave. It's a one-time process that's far easier to sort out at home with a stable connection than abroad, possibly with unfamiliar networks or a language barrier.
Do eSIMs cost more than physical local SIMs?
It varies by destination and provider — compare a couple of options for your specific trip rather than assuming either is always cheaper.
What about a short weekend trip — is it still worth unlocking?
If you'll be there long enough to need meaningful data, a local SIM or eSIM is usually still cheaper than a short burst of roaming — and since the unlock itself is permanent, it pays off on every future trip as well, not just this one.
Enter your IMEI and current network to see your price.
