When you're abroad, the SMS verification codes you usually take for granted can become surprisingly hard to receive. Waiting for a code sent to your phone number — for logins or identity checks — is one of the easier things to trip over while traveling or staying overseas. This guide walks you through how to set things up before you leave so you don't have to depend on SMS verification at all, by switching to an authenticator app (a two-factor authentication app), explained clearly enough for first-timers.
- Switching to an authenticator app (TOTP) before you travel gives you peace of mind abroad
- Authenticator apps generate codes without any connection, and you don't need to keep a phone number active
- Banks, brokerages, and credit cards may still require SMS and not support authenticator apps
- Bloomy is data-only — it can't receive SMS sent to a phone number or make voice calls
- Phone-number calls and SMS aren't possible, but app-based calls like WhatsApp work over data
The short version
- Many services (Google, Apple, major social and cloud platforms, and more) often let you switch from SMS to receiving codes through an authenticator app (TOTP) instead. App-generated codes don't require a connection, which makes them less affected by network conditions when you're abroad.
- That said, some services — particularly banks, brokerages, and credit cards — may be built around SMS or their own dedicated apps, and may not let you switch to an authenticator app. In those cases, you'll need a separate way to receive SMS messages while traveling.
- It's safest to get this done before you leave, while you can still receive codes sent to your number.
* This article reflects general information as of June 2026. How each service handles this can change, so please check the official guidance from each provider for the latest details.
Why SMS verification often trips people up abroad
SMS verification works by "sending a code to a registered phone number." When you're abroad, your plan status, roaming settings, or local network congestion can mean codes arrive late or don't arrive at all. This is especially true during long stays or study-abroad periods, when you may have canceled or suspended your home phone number and can no longer receive codes in the first place.
This is where an authenticator app (two-factor authentication app) helps — it doesn't depend on SMS sent to a number. Switch over before you go, and you can cut down on the anxiety of waiting for an SMS every time you log in abroad.
What is an authenticator app (TOTP)? How it differs from SMS verification
An authenticator app generates a roughly six-digit one-time code that changes at regular intervals, right on your phone. Well-known options include Google Authenticator and Microsoft Authenticator. Because generating the code itself doesn't use any connection, you can still see your code even where the signal is weak.
| Aspect | SMS verification | Authenticator app (TOTP) |
|---|---|---|
| How you get the code | SMS to your phone number | Generated automatically in the app |
| Reliability abroad | Easily affected by network and plan status | Generated without a connection, so less affected |
| Keeping a number active | Generally required | Often not required |
| Main thing to watch | Stops working if you change or cancel the number | Needs transfer setup when you change phones |
The key point: with an authenticator app, you can usually have verification codes ready even without keeping a phone number active. On the other hand, it's important to store your backup codes in case you change phones or lose your device.
How to switch over before you leave
Screen names vary by service, but the overall flow is much the same. Get it done while you're still at home.
- List the services you care about: email, social accounts, cloud storage, shopping — anything you're likely to log into while traveling.
- Open each service's "Security" settings: look for two-step or two-factor authentication options.
- Add an authenticator app: scan the QR code shown with your authenticator app, then enter the code it displays to register.
- Save your backup codes: write them down on paper, or store them in a password manager — somewhere other than the phone itself is safest.
- Confirm it works: log out once and try logging back in using the code from your authenticator app.
Setting up one service often takes just a few minutes, but it adds up if you have many. We recommend getting started with plenty of time to spare, not right before departure.
Some services can't be switched (banks, brokerages, credit cards)
One thing to keep in mind: not every service supports authenticator apps. In particular, financial services such as banks, brokerages, and credit cards may be built around SMS or a dedicated app for identity checks, and may not let you switch to an authenticator app. In those cases, you'll need a separate way to receive SMS while you're abroad.
If you plan to use financial services while traveling, also see our guide to receiving SMS verification abroad — how to avoid trouble with banks, brokerages, and credit cards. The practical approach is to use both: move what you can to an authenticator app, and prepare an SMS option for what you can't.
What you can and can't do with Bloomy's data-only eSIM
Many people use a data-only eSIM like Bloomy eSIM to stay connected abroad. To be clear up front, Bloomy's plans are data-only by design. They can't be used to receive SMS sent to a phone number. That said, data connectivity helps in situations like these:
- Opening an authenticator app or a login screen (generating the code itself needs no connection, but the login action requires data)
- Receiving in-app notifications or push-based approvals (for services that support them)
- App-based calls and messaging such as WhatsApp (available where a data connection is usable)
In other words, combining "prepare your identity checks with an authenticator app" + "provide data connectivity with an eSIM" makes it easier to reduce login-related worries while traveling. If you need SMS sent to a number or voice calls, look into options beyond a data-only eSIM as well, such as a local SIM or a plan that includes a phone number.
Common pitfalls and how to handle them
Prepare for changing phones or losing your device
Because authenticator apps create codes on the device itself, you can get locked out if you change phones or lose your device without preparing to transfer. Store each service's backup codes, and check your authenticator app's own transfer and backup features.
Clock drift can reject your codes
Authenticator codes are generated based on the time, so if your device's clock is significantly off, even a correct code can fail. Setting your phone's time to "automatic" is the safe choice.
Trying to switch everything and panicking at the last minute
With many services, finishing them all before departure is a lot of work. Starting with the high-priority ones — finance, email, the apps you use most — helps you avoid leaving anything out.
Want to review all your pre-travel prep in one place?
The right choice for connectivity at your destination depends on data volume, number of days, and the countries and regions supported. From the Bloomy eSIM comparison page, you can search for plans by country, data volume, and duration. The plans and terms actually available can differ by country and region, so please check the latest details before purchasing. If you get stuck on setup or usage, our FAQ can help, and you can find more on phone-number and SMS topics in the phone number & SMS article list.
In summary
The trick to not being at the mercy of SMS verification abroad is simple: before you leave, switch over anything that can move to an authenticator app. Without depending on SMS sent to a number, you're far less affected by network conditions overseas. But since some services — banks, brokerages, credit cards — can't be switched, cover those with an SMS option and use each approach where it fits. Provide connectivity with a data-only eSIM, and handle verification with a little preparation in advance. That alone goes a long way toward easing the small login-related worries of traveling.
Note: Bloomy is a data-only eSIM (no phone number, SMS, or voice calls) and is subject to a fair use policy. Connection quality varies depending on the local network, your device, and your location.
