Every traveller eventually faces the same question at the airport gate: how am I going to get online when I land? The three usual answers are staying on your home network’s roaming, buying a local physical SIM, or installing a travel eSIM. Each has trade-offs in cost, convenience and reliability, so here is a straightforward comparison to help you choose.
Option 1: Roaming on your home SIM
Roaming means your usual network lets you connect to a partner network abroad, usually for an extra daily or per-megabyte fee unless your plan already bundles it in. Inside the European Union, roaming rules are capped for EU residents travelling within the bloc under “roam like at home” rules, which you can read about on the European Commission’s roaming policy page. Outside those specific arrangements, roaming can be the most expensive option, particularly for data-heavy use like video calls, maps or streaming.
Pros: No setup needed, your existing number keeps working exactly as normal.
Cons: Often the most expensive option outside capped zones, and easy to run up a large bill without noticing.
Option 2: A local physical SIM
Buying a SIM card from a shop or kiosk at your destination can be cheap, but it comes with friction: you need to find a shop, show identification in some countries, physically swap the card, and remember to switch back before you fly home. If your phone does not support a second SIM slot, you also lose access to your home number for the length of the trip.
Pros: Often low cost once you are set up.
Cons: Time spent finding a vendor, potential language barriers, a lost home SIM while travelling, and a tiny piece of plastic that is easy to misplace.
Option 3: A travel eSIM
A travel eSIM, like the plans on OneSim, is a digital SIM you buy online before you fly. You pay by card, Apple Pay, Google Pay or Link, and the eSIM (QR code, one-tap iPhone install link, and manual activation details) is delivered by email within minutes and saved in your customer dashboard. For most plans, validity starts only once the eSIM connects to a network at your destination, so you can install it well ahead of your trip without wasting days.
Pros: Set up before you leave home, your normal SIM stays in the phone for calls and texts, no shop visits, and easy top-ups from your dashboard if you run low.
Cons: Requires an eSIM-compatible phone, which you can check with our device compatibility checker.
Side-by-side comparison
- Setup time: Roaming, none; local SIM, 15 to 60 minutes including travel to a shop; eSIM, a few minutes online, before or after landing.
- Typical cost for data-heavy trips: Roaming is usually highest outside capped zones; eSIM and local SIM are usually lower and more predictable, since you choose a fixed data allowance upfront.
- Keeping your home number active: Roaming, yes; local SIM, only with a dual-SIM phone; eSIM, yes, since it runs alongside your existing SIM.
- Availability on arrival: Roaming and eSIM both work as soon as you land; a local SIM depends on finding an open shop.
Which should you choose?
If your trip is short and light on data, checking your existing roaming allowance may be enough. For anything longer, or for regions where roaming charges from your provider are steep, a travel eSIM is generally the most convenient middle ground: it is set up before you leave, keeps your existing number reachable, and avoids the language and logistics of hunting down a local SIM. According to the GSMA, eSIM adoption has grown steadily worldwide precisely because it removes this kind of friction from travel.
FAQ
Can I use an eSIM instead of roaming completely?
Yes. Once your eSIM data plan is active, you can turn off data roaming on your home SIM and rely on the eSIM for internet access, while keeping your home SIM available for calls and texts.
Will a local SIM always be cheaper than an eSIM?
Not necessarily, once you account for travel time, potential language barriers, and the hassle of swapping cards. A travel eSIM often costs about the same while saving considerable time and effort.
Do I need to remove my physical SIM to use an eSIM?
No. On a dual-SIM phone, the eSIM works alongside your existing physical SIM, so there is nothing to remove.
Ready to skip the roaming bill and the SIM shop queue? See plans for your destination on our local eSIMs page.