Three ways to have working data abroad. None is best for everyone.
Quick comparison
| Travel eSIM | Local physical SIM | Home-carrier roaming | |
|---|---|---|---|
| Setup effort | Buy and install before you fly | Shop/kiosk on arrival, sometimes ID and a queue | None — it just works |
| Cost per GB | Mid-range | Usually cheapest, especially in Asia | Usually most expensive |
| Keeps home number active | Yes, alongside it | Only if you use a second SIM slot | Yes — it is your home number |
| Local phone number | No (data-only, with rare add-ons) | Yes | N/A (your home number) |
| Best trip length | Short to mid-length trips | Longer stays, data-heavy trips | Very short trips (2–3 days) |
Travel eSIM
Good: Set up before you leave; working data the second you land; keep your home number active alongside it; easy to compare prices in advance; no shop visit, no passport photocopy.
Bad: Data-only (no local number); per-GB cost is higher than a local SIM in cheap-data countries; needs an unlocked, eSIM-capable phone.
Best for: Most short and mid-length trips; anywhere SIM registration is a hassle (India, Thailand’s tourist queues); people who want it sorted from home.
Local physical SIM (bought at destination)
Good: Cheapest per GB, especially in Asia; often includes a local number and calling credit; big data allowances.
Bad: Costs you time on arrival (airport kiosk markups, or a town-centre shop); registration with ID in many countries; you swap out your home SIM (or use a second tray); quality varies by which kiosk you use.
Best for: Long stays; data-heavy trips; countries where local data is very cheap and kiosks are easy (Thailand, Vietnam, Indonesia, Turkey).
Home-carrier roaming pass
Good: Zero setup; your normal number just works for calls and texts; fine for a short trip.
Bad: Usually the most expensive per day; “unlimited” is often throttled hard; some plans exclude your destination.
Best for: Very short trips (2–3 days); people who must keep their normal number fully working for calls/SMS; anyone who values zero effort over cost.
A rough cost example
Numbers vary a lot by country and provider, but as a feel for the shape of it — a traveller needing about 10GB for a one-week trip to a mid-cost destination typically sees:
- Home-carrier roaming pass: often the highest daily rate of the three, sometimes charged per day regardless of how much data is actually used.
- Travel eSIM: a 10GB-or-unlimited-for-a-week plan usually lands well below the roaming pass — see this site’s country pages for verified current prices.
- Local physical SIM: frequently the cheapest per GB in Asia and parts of Europe, but factor in the kiosk markup and the time spent buying it, which a pure per-GB comparison misses.
The eSIM’s advantage isn’t always the lowest sticker price — it’s the combination of a reasonable price and zero time lost on arrival.
A common setup that works well
Keep your home SIM active for calls and 2FA, and add a travel eSIM for data. You get your normal number and cheap data at the same time, with nothing to swap. If you’re going somewhere with very cheap local SIMs and staying a while, buy a local SIM on arrival instead of a large eSIM plan.
FAQ
Can I use all three at once? Not usefully — most phones support one physical SIM plus one eSIM, or two eSIMs, active at a time. The practical combination is home SIM (calls/texts) plus one data source (eSIM or local SIM), not roaming on top of both.
Is it ever worth buying a roaming pass just as a backup? Rarely — if the eSIM fails to activate, most travellers troubleshoot it (see the install guides) rather than pay roaming rates as insurance. Buying the eSIM a day or two before you fly, while you still have Wi‑Fi to fix any install issue, avoids needing a backup at all.
Does switching between these mid-trip cause problems? No — you can install a local SIM partway through a trip if your eSIM data runs out and you decide it’s cheaper to switch, or vice versa. There’s no lock-in; each is just a data source you can swap.
Start with what an eSIM actually is if any of this is unfamiliar, or jump to sizing a plan if you’ve already decided an eSIM is the way to go.