Roaming in Europe as a US Traveler: eSIM vs. Carrier Day Pass

Here is the short answer for anyone landing in Europe tomorrow: you can use your US phone in Europe without swapping any SIM card. Your carrier sells a day pass for around $10 to $12 that activates the moment you use data or make a call. For a long weekend, that is often the simplest thing to do. For a trip longer than four or five days, or if you are moving between multiple countries, buying a travel eSIM before you fly will almost certainly cost less and work just as well.

The rest of this post explains how both options actually work, what each of the big US carriers charges, why you keep seeing ads for "EU roaming included" plans that do not apply to you as an American, and what to do about two-factor authentication codes while you are abroad.

What your US carrier charges for a day pass in Europe

The three major US carriers all sell what amounts to a "roaming day pass": a flat daily fee that lets you use your existing domestic plan while abroad. These prices were re-verified on the carriers' own pages on 14 August 2026. Carrier pricing changes without notice and without announcement, so confirm the current figure on the carrier's own page before you buy.

Verizon TravelPass costs $12 per day in most countries, including all of the EU, the UK, Croatia, and most of the rest of Europe. You get 5 GB of high-speed data per day before speeds drop to 3G. The pass is only charged on days you actually use the phone, so you are not paying for travel days where you stay on airplane mode.

Verizon also sells an International Monthly Plan at $100 per line per month, with 250 minutes, unlimited texts, and unlimited data where the first 20 GB is full speed and the rest drops to 3G. Verizon pitches it at trips of nine days or more, and the arithmetic agrees, since TravelPass at $12 a day passes $100 on day nine. For a two week European trip, TravelPass would be $168 against $100 for the monthly plan. If you are on Verizon and away for longer than eight days, compare the two before defaulting to the daily pass.

AT&T International Day Pass also costs $12 per day per line, covering 210 plus destinations. Your domestic unlimited plan's full data follows you, so you are not given a separate data bucket. If you have multiple people on your account traveling together, each line pays $12, though each additional line on the same calendar day costs $6 (so two people traveling together pay $18 total for that day, not $24).

T-Mobile depends entirely on which plan you are on, and the plan names changed recently, so check rather than assume. On Experience Beyond, 15 GB of high-speed international data is included at no extra daily charge, then unlimited at up to 256 Kbps. Experience More includes 5 GB at full speed before slowing to the same. Essentials includes texting and calls at $0.50 a minute but no high-speed data, so you would need to buy a pass. On older Magenta or ONE plans you get unlimited data abroad at 256 Kbps by default, which is fine for maps and messages and not much else. If you need full-speed data on any T-Mobile plan, a 1-day International Pass is $10 with 2 GB, the 10-day pass is $50 with 15 GB, and the 30-day pass is $75 with 30 GB.

If you do not add any plan and use your phone abroad anyway, the pay-per-use rates are genuinely alarming. AT&T publishes $2.05 per megabyte, which works out to roughly $2,000 per gigabyte. Turn on airplane mode and enable Wi-Fi only until you have sorted your data plan, especially if your phone automatically downloads updates.

What "roam like at home" means, and why it does not help you

You may have seen European SIMs or European residents talking about roaming across the EU with no extra charges. That refers to EU Regulation 2022/612, which bans roaming surcharges for people with a phone plan from an EU or EEA member state. A German person with a German SIM can use their phone in Greece, Croatia, or Portugal as if they were still in Germany, because the regulation requires it.

This does not apply to you. Your phone plan is from the United States, which is outside the EU/EEA. A US carrier is not bound by that regulation. You pay whatever your US carrier charges, regardless of which EU country you are standing in. The regulation is a real benefit, but it is a benefit for residents, not visitors.

If you buy a travel eSIM or a local SIM while in Europe, and that SIM is from a carrier with EU roaming included, then you would benefit from the regulation for travel within the EU. That is part of what makes an EU-registered eSIM appealing for multi-country trips.

Photo by Anastase Maragos on Unsplash

How eSIMs work and which phones support them

An eSIM is a digital SIM card built into your phone. Instead of buying a small physical plastic card and pushing it into a tray, you download a profile, usually by scanning a QR code. Your phone can hold multiple eSIM profiles, so you can have your US number active at the same time as a travel eSIM, which matters for receiving calls and two-factor codes.

Most phones bought in the last four or five years support eSIM. iPhone XS and later, Google Pixel 3 and later, Samsung Galaxy S20 and later, and most other flagship Android phones released since 2020 are compatible. If you bought your phone directly from a carrier on a payment plan rather than unlocked, check whether it is carrier-locked before you travel. A locked phone will not accept any SIM or eSIM from a different carrier. You can request an unlock from your carrier once you meet their terms, which typically means the device is paid off and your account is in good standing.

To check whether your phone supports eSIM, go to Settings, search for "eSIM," or look at the cellular settings for an "Add eSIM" or "Add cellular plan" option. Apple also lists supported devices at apple.com/iphone/cellular.

Travel eSIM providers like Airalo sell data-only plans for Europe at prices that are significantly lower than carrier day pass rates for trips longer than a few days. A typical Europe-wide eSIM from Airalo (covering 39 countries including Germany, Greece, and Croatia) might run $8 to $15 for 5 GB, or $20 to $30 for 20 GB, covering a multi-week trip. These are data-only plans, meaning you get mobile data but no local phone number. Your US number stays on your home SIM and still receives calls and texts. Saily is another reliable option worth comparing, particularly if you find Airalo's plan options do not fit your itinerary.

The practical setup before you fly

The right sequence matters, and doing it in the wrong order causes headaches.

Buy and install the eSIM at home, before you leave. Downloading the eSIM profile requires a decent internet connection. Do it on your home Wi-Fi rather than trying to do it at the airport or after landing. Scan the QR code, let the profile install, and confirm it appears in your cellular settings.

Leave the eSIM disabled until you land. Once the profile is installed, you can turn it on and off in your phone settings. Leave it off during your flight. When you land, go to Settings, find the travel eSIM, turn it on, and make sure data roaming is enabled for it.

Keep your home SIM active for calls and texts. You will still receive calls and text messages on your US number as long as your home carrier SIM (or eSIM profile) stays active. Your phone will use your home number for calls and your travel eSIM for data. This is called dual-SIM mode, and iPhones and most modern Androids handle it automatically.

Set your data preference to the travel eSIM. In your phone's cellular settings, there is usually an option for "Default Line" or "Cellular Data" that lets you choose which SIM handles data. Set this to your travel eSIM so you are using the cheaper data plan rather than triggering a $12 day pass.

Photo by User_Pascal on Unsplash

What to do about two-factor authentication

This is the practical problem that worries people most. Most banking apps send a one-time code by SMS when you log in from a new location. If your phone is abroad, those SMS messages arrive on your US number, which stays active as long as your home SIM is still in the phone. Since you are keeping your home SIM active in dual-SIM mode, you receive those codes exactly as you would at home.

Where it breaks down is if you have removed your physical SIM to make room for a travel SIM, or if your phone only has one SIM slot. In that case, your US number is unreachable for SMS unless you have set up Wi-Fi calling. The cleaner fix: switch your most important accounts to an authenticator app like Google Authenticator or Authy before you leave. Authenticator apps generate codes offline, so they work anywhere without any cellular connection.

Two things to do before you fly: log in to your bank and email from home (which often satisfies the "new location" check for a while), and look at whether those accounts let you switch to app-based 2FA. If you use a Wise card for travel spending, you can manage most account tasks over Wi-Fi anyway, and Wise also avoids the international transaction fees that most US cards add to purchases abroad.

When a carrier day pass actually makes sense

An eSIM takes about ten minutes to set up, and it requires doing it ahead of time, checking that your phone supports it and is unlocked. For some trips, the day pass is the simpler choice.

A trip of three or four days in one country is a reasonable candidate. Four days at $12 is $48, and some single-country eSIM plans cost nearly as much once you factor in setup time.

If you are on T-Mobile Experience Beyond or Experience More, check your plan first. You may already have 5 to 15 GB of included international high-speed data, which can be enough for a short trip without any extra purchase.

If something goes wrong with your eSIM mid-trip, your carrier day pass is the immediate fallback you can turn on from your carrier's app.

When eSIM wins

Trips longer than five or six days. The math shifts clearly in favor of an eSIM once you are past the point where the daily fees add up to more than a prepaid data plan.

Multi-country routes. Going from Germany to Greece to Croatia in one trip? A Europe-wide eSIM from Airalo covers all three with one purchase. Carrier day passes work in all those countries too, but you are paying the daily fee in each one regardless.

Traveling with multiple people on the same itinerary. If two of you are going for ten days, that is potentially $240 in carrier day pass fees. A pair of eSIMs covering the same period would likely cost a fraction of that.

Older phones that are already unlocked and travelers who are comfortable in their phone settings will find eSIM setup quick enough that it pays off even on shorter trips.

The honest trade-off

Neither option is universally better. A carrier day pass is convenient for short trips where you want zero setup and are comfortable paying for simplicity. An eSIM saves money on longer or multi-country trips but requires doing the setup before you leave.

The one option that is clearly not good: doing nothing. If your phone connects to a European network without any plan in place, pay-per-use rates can add hundreds of dollars to your bill before you notice.

Before you go

Connectivity is one of the practical details that can either set your trip up or add stress to it. Getting this sorted before you land is worth the time. The TravelReddi guide for your destination covers eSIM recommendations alongside entry requirements, local app tips, and other things to know before you fly. Check the guide for Germany, Greece, or Croatia depending on where you are headed.