When figuring out how to stay in touch while studying abroad, many people consider a "phone number app (VoIP)." Services such as TextNow, Google Voice, and similar apps let you make and receive calls and messages on a phone number using your data connection — a handy setup. That said, they don't replace a regular mobile number in every situation, and some banks and services won't accept them for identity verification. This article sorts out what phone number apps can and can't do while you're abroad, and how to pair them with a data-only eSIM so you can feel prepared — written to be easy to follow even on your first trip overseas.
The short answer
- Phone number apps (VoIP) use your data connection to make and receive calls on a number, and to send some messages.
- Which countries are supported, the type of number you can get, and whether SMS works all vary from one service to another.
- They may not work for identity checks or SMS verification with banks and certain services.
- The "data connection" that powers those calls and messages is best arranged with a data-only eSIM.
- For important verifications, it helps to also keep a SIM or number from your home country, or another backup method, ready.
If you remember two things — don't rely on a phone number app alone, and lock in your data connection with an eSIM — you'll rarely get stuck for ways to stay in touch while abroad.
What is a phone number app (VoIP)?
A phone number app (VoIP) is a service that lets you make calls and send messages on a phone number over an internet connection (your data). VoIP stands for "Voice over Internet Protocol" — a technology that carries your voice over the internet instead of a traditional phone line.
Apps like TextNow and Google Voice are common examples. Once you install the app and get a number, you can make and receive calls on that number wherever you have Wi-Fi or mobile data. The fact that you can hold a number without a physical SIM card or a line contract is exactly why these apps catch the eye of students living abroad.
Keep in mind, though, that the countries and regions these services cover, the kind of number you can obtain (a local number, a number from another country, and so on), and whether you can send and receive SMS differ greatly between services. "Any app works the same way" simply isn't true, so it's worth checking each provider's official information before you rely on one.
What phone number apps can do
While abroad, the appeal of a phone number app is that "as long as you have data, you can use a number." Here's a look at the main things they can do.
Calls over your data connection
Wherever you have Wi-Fi or mobile data, you can make calls on your number through the app. Because it uses the internet rather than a phone line itself, the experience tends to be smoother in places where your data connection is stable.
Messages with other app users and supported contacts
Depending on the service, you can exchange text messages. These are often centered on people using the same app or on supported numbers, and whether they go through as standard SMS varies by service.
Some SMS, depending on the service
Some VoIP services support sending and receiving SMS within certain limits. However, it doesn't mean "every SMS will arrive or send," and verification texts from banks and similar institutions in particular may not come through. We cover this in more detail under "What they can't do" below.
What phone number apps can't do, or struggle with
For all their convenience, phone number apps have situations they're not good at. Knowing these before you go makes it far less likely you'll be caught out when it matters.
SMS verification for banks and some services
Banks, credit cards, and some online services may use SMS verification (such as one-time passwords) sent to a registered mobile number to confirm your identity. A VoIP number may not be able to receive these verification texts, which can leave you stuck partway through an important process.
Use in unsupported countries or regions
With some services, you can only get or use a number in certain countries, or the country where you're studying may not be supported at all. It's reassuring to confirm whether a service works at your destination by checking its official information before you leave.
Emergency and other special calls
By design, VoIP may not support special calls like emergency services, or may handle them differently from a regular mobile line. It's wise to plan your way to reach help in a real emergency on the assumption that you won't rely on VoIP alone.
Quick comparison: what they can and can't do
| Item | Phone number app (VoIP) | Notes |
|---|---|---|
| Calls over data | Usually possible | Needs a data connection |
| Messages between app users | Usually possible | With supported contacts |
| General SMS | Varies by service | Coverage differs widely |
| Bank-style SMS verification | May not work | Keep a backup method ready |
| Use in unsupported countries | May not work | Check supported countries first |
| What it needs to work | A data connection | Secured with a data-only eSIM, etc. |
* Availability may change depending on the service and timing. Please check each app's latest information before use.
How to put your communication setup together while abroad
A phone number app is appealing because "you get to keep a number," but as you can see, it's hard to cover everything with the app alone. To avoid trouble while studying abroad, it helps to divide the roles and prepare like this:
- Data connection: Secure it with a data-only eSIM. VoIP apps and calling/messaging apps such as WhatsApp can often be used as long as your data connection is working.
- Everyday contact: Center it on app calls and messages (WhatsApp and similar). Agreeing in advance with family and friends on which app to use makes things smooth.
- Important verification: For SMS verification with banks back home, keep a SIM from your home country or another method ready. Thinking ahead about how to keep verification from stalling — including help from family or a trip back home — adds peace of mind.
Splitting things into "data connection," "everyday contact," and "identity verification" makes it much easier to see what you need to prepare and where.
Things to note (data-only eSIM and connection quality)
- Bloomy eSIM is fundamentally a data-only eSIM. A phone number, SMS, and voice calls themselves are generally not included. That said, apps that run on data (VoIP apps, messaging apps, and so on) can often be used wherever you have a working data connection.
- Phone number apps (VoIP) may not work for SMS verification with banks and some services. When you need a number, SMS, or voice, please also check a separate method.
- Connection quality and each service's specifications can vary or change depending on the local network conditions, coverage area, congestion, your device, and the provider. Please confirm the latest conditions before you buy and before you use the service.
- VoIP services' pricing and supported regions can change. For free tiers and supported countries, it's safest to check the latest details in each app's official information.
What you can do with Bloomy eSIM
Bloomy eSIM offers a comparison page where you can choose a plan by country, data allowance, and number of days — designed so first-time eSIM users and students traveling abroad won't feel lost. You can arrange the "data connection" that powers phone number apps (VoIP) and messaging apps to match your destination.
If you're thinking, "I have a number, but I'm not sure how to set up the data connection that runs it," it becomes easier to plan once you first secure your data with a data-only eSIM and then build your communication setup on top of it.
Frequently asked questions
Can phone number apps be used for free?
Some services offer a free tier, but the available features and supported regions can change. Because the free scope and the conditions for paid use differ by service, please check each app's latest information.
Can I use one for SMS verification with services in my home country?
It may not work. With important verifications such as banks in particular, texts may not arrive, so it's reassuring to also have a SIM from your home country or another method ready.
How should I arrange my data connection?
A data-only eSIM is the standard way. On Bloomy eSIM's eSIM comparison page, you can check plans that fit your destination and the number of days you'll travel.
Do I need a VoIP app or an eSIM?
They serve different roles, so combining both is the basic approach. An eSIM provides your data connection, while a VoIP app uses that data connection to make calls and send messages on a number.
Can I get a phone number with Bloomy eSIM?
Bloomy eSIM is fundamentally data-only. A phone number, SMS, and voice calls themselves are not included, though apps that run on data can often be used. If you need a number, please also check a separate method.
Related links
- Can an eSIM alone give you a phone number? Calls, SMS, and verification explained
- What is a VoIP number? Why it may not work for banks and verification
- Pre-departure checklist: getting your data connection (eSIM) and phone number ready
- eSIM comparison page
In summary
Phone number apps (such as TextNow and Google Voice) are a handy way to make calls and send messages on a number using your data connection — but they aren't a cure-all. They may not work for SMS verification with banks, and supported countries differ from service to service. To stay out of trouble while studying abroad, it's reassuring to divide the roles in advance: "secure your data connection with a data-only eSIM," "handle everyday contact with app calls and messages," and "cover important verification with a SIM from your home country or another method." If you'd like to understand how it all works in more detail, see Can an eSIM alone give you a phone number? Calls, SMS, and verification explained; if you want to arrange a data connection for your destination, take a look at the eSIM comparison page.
