Your carrier's international roaming plan is priced for people who don't know there's a better option. T-Mobile's Magenta plan gives you free international data, which sounds great until you discover it's throttled to 2G speeds. Fine for directions, unusable for anything else. Verizon's TravelPass charges $10 per day, which adds up to $100 on a ten-day trip before you've done anything useful with it. AT&T is similar. None of these are bad products. They're just priced at the convenience premium, and that premium is significant. Here's how to decide which option makes sense for your trip.
The Three Options, Clearly
Local SIM. You buy a physical SIM card at or near your destination, typically at the airport, a convenience store, or a carrier shop. Swap it into your phone, follow a few setup steps, and you have local data rates for the duration of your stay.
eSIM. An embedded SIM that downloads digitally to your phone before or after you arrive. No physical card swap. Activate it when you need it, deactivate when you're done. Works on most phones made since 2018, and any iPhone from the 12 onward.
International roaming. Keep your home SIM, activate your carrier's travel plan, and use your regular number everywhere. Zero friction. Pay the premium.
The right answer depends on your phone, your trip length, the countries you're visiting, and how much connectivity you need.
Local SIMs: Best Price, Most Friction
If you want the cheapest data available, a local SIM is almost always the answer. Carriers in Southeast Asia, Europe, and much of Latin America sell tourist SIMs with generous data allowances, often 5–15 GB of fast data, for $5 to $20. For context: that same $20 buys you two days of Verizon TravelPass.
The friction is real. Your phone must be unlocked (most U.S. phones sold outright are; phones on payment plans through carriers often aren't). Check before you leave. You need to physically swap SIMs, which means keeping your original SIM somewhere safe for two weeks. Setup occasionally requires fiddling with APN settings. And you'll get a local phone number, which matters if anyone needs to reach you on your usual number while you're away.
For most international trips over a week, the savings justify the friction. For a long weekend in Canada or a quick European layover, probably not.
Where to buy: Airport SIM kiosks work and charge a small premium for the convenience. Convenience stores (7-Eleven in Southeast Asia, tobacconists in Europe) and carrier shops in city centers are usually cheaper. In many countries (Thailand, Japan, Italy), airport options are genuinely competitive.
Countries with particularly good options: Thailand (DTAC, True Move), Japan (IIJmio, Sakura Mobile), the UK (Three, EE), and most of Western Europe offer excellent tourist SIMs. The U.S. and Canada have less competition and higher prices, which is why TravelPass looks reasonable by comparison.
eSIMs: The Convenience Play, Getting Better Fast
Three years ago eSIMs were a promising technology surrounded by a frustrating ecosystem. Today they're a legitimately good option for most travelers with compatible phones.
The workflow: download an eSIM app or buy a data plan from a provider like Airalo, Holafly, or Nomad before you travel. Scan a QR code, follow a few steps, and the plan activates when you arrive. No SIM swap, no hunting for a carrier shop in an unfamiliar airport, no local phone number complications.
Airalo is the largest eSIM marketplace and the most commonly recommended. Plans run slightly more than a local SIM but significantly less than carrier roaming. A 3 GB eSIM for Thailand runs about $5–$8 through Airalo; comparable plans for Europe run $8–$15. Data-only, no calls or texts, but WhatsApp, FaceTime, and Signal handle those over data anyway.
Holafly differentiates with unlimited data options, which matter if you're video calling frequently or working remotely. Unlimited eSIMs for Europe run $20–$35 for ten days, more than data-only options, but simpler than managing GB limits.
The limitations: eSIMs work best when data is the only thing you need. If you need an actual local phone number (for two-factor authentication texts sent to a local number, for calling local businesses, for anything requiring a receivable SMS), you need a local SIM instead. And eSIM compatibility is not universal. Carrier-locked phones, older Android models, and some budget phones don't support eSIM at all.
Check compatibility at esimdb.com or your provider's compatibility page before buying. Discovering your phone doesn't support eSIM while standing in the arrivals hall is a specific kind of frustration.
International Roaming: When to Just Pay for It
Carrier roaming isn't always the wrong answer. It's the right answer in specific situations.
Short trips. Three days in the UK for a conference doesn't justify the friction of a SIM swap. At $10 per day, Verizon TravelPass for three days costs $30, comparable to what you'd spend on an eSIM and considerably less hassle.
Emergency backup. Keep your home plan active and add a local SIM or eSIM as your primary. If the local option fails, you have a fallback. Many experienced travelers do this: use the cheap local option day-to-day, keep roaming in reserve.
Calls matter. If people need to reach you on your regular number (work calls, family emergencies, two-factor authentication codes sent to your number), roaming keeps that continuity. Forwarding your number to a VoIP service and calling over data is an option, but it adds setup complexity.
T-Mobile's free international data deserves its own mention. Magenta and higher plans include free data in 215+ countries. The throttling to 256 kbps is significant. You won't stream video, and loading a map takes several seconds, but for messaging, directions, and light email, it works. If you're on T-Mobile and making a short trip, it's worth trying before you spend anything.
Multi-Country Trips: Where It Gets Complicated
A two-week trip covering five European countries has options that a single-destination trip doesn't.
EU regulations mean that a SIM sold in any EU country gives you data across all EU member states at no extra charge. Buy a SIM at Amsterdam Schiphol, use it in France, Italy, Spain, and Germany. This makes a single EU SIM a genuinely compelling option for European multi-country trips.
Outside the EU, this math changes. A Thailand SIM doesn't cover Vietnam or Cambodia at local rates. For Southeast Asia multi-country trips, a regional eSIM plan (Airalo offers multi-country options) or separate SIMs per country are the alternatives.
Regional eSIM plans are available for North America, Europe, Southeast Asia, and most other major travel regions. They're priced between a local SIM (cheapest) and roaming (most expensive), and they work across all countries in the region. Simpler than juggling multiple SIMs; more expensive than buying local per country.
Making the Decision
Three questions get you to the right answer.
Is your phone unlocked and eSIM-compatible? If you don't know, find out before you pack. An unlocked eSIM-compatible phone opens all three options. A locked phone limits you to roaming unless you can get it unlocked first.
How long is the trip and how many countries? Under three days: roaming. Three to seven days, single country: eSIM. Over a week, single country: local SIM or eSIM at similar cost, local SIM wins on price. Multi-country in the EU: EU SIM. Multi-country outside the EU: regional eSIM.
Do you need calls and SMS, or just data? Data-only: eSIM. Calls and texts to local numbers: local SIM. Calls and texts on your regular number: roaming.
Most travelers end up on eSIM for trips over a week and roaming for short trips, with local SIMs reserved for long stays or destinations where the price difference is substantial. The edge cases (remote destinations, locked phones, complex multi-country itineraries) are where it's worth spending an extra twenty minutes comparing before you leave.
