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It’s possible that you’ve noticed that the least important part of your phone is how it serves as a telephone. Now that mobile devices are (rightly) thought of as an ultra-portable computing device, it can be easy to overlook how you’ll stay in touch when traveling abroad. Of course, being able to make phone calls to businesses and service around you while you travel in another country can be convenient, or necessary, depending on which country you’re traveling in. Today, we’ll take a look at some options for staying in touch by communicating over the internet instead of a phone line.

All digital, all the time

Back when WhatsApp emerged in the calling space around 2015, calls became just a normal part of messaging. This type of free service was basically impossible before: the infrastructure needed to run an international phone system was expensive to build and maintain. Phones and computers typically used separate infrastructure to reach each other, except for that period (up to the 1990s) where we used the phone system to dial into our ISP, who could then connect us to the internet.

Once the global network infrastructure was in place to make the internet run on network cables instead of phone lines, it was only a matter of time for the throughput of that network to increase enough to reliably stream real-time audio (and video) data between individual users. Since it all became digital communication eventually, there’s really no limit to what kind of data can be sent over the internet—just how fast it can be sent. In some parts of the world, the internet was made available along with the rise of smartphones, and the infrastructure has been developed around digital, wireless technologies.

With the infrastructure to transmit digital information across the globe, all that was needed was for the speed and quality of the internet to stay high, and for software/applications that can send audio across the web from user to user. When apps like WhatsApp—which was already a popular messaging app around the world before it introduced calling on the web—and Skype made it free to call any other user, it took away the need for international calling plans on your phone, just like texting with it had been cost-free to the user.

Planning for calling when abroad

Most of the calling solutions out there treat your phone number as still in your home country. This means that making public-switched calls (typical phone calls using the phone system, as opposed to private branch exchange) will be treated as an international call, even if you are a few blocks away—your number stays home while you’re abroad. WhatsApp, though, just uses phone numbers as a way of identifying users, so you don’t have to worry about where a number is based.

Google Voice and Teams, on the other hand, use a hybrid approach to calling that allows you to use either; this means you need an international calling plan through your carrier or through Microsoft, respectively, to make phone calls in the country you are visiting. Because of this, WhatsApp is probably the best way to make calls, as long as the people and businesses you are calling use the app.

Find out if WhatsApp is commonly used in the country you’re visiting, alongside the research you need to do to figure out if your phone will work there. To do this research, I recommend looking at forum posts and asking others who have experience travelling to the country you plan to visit. Reddit posts are a great tool here: many subreddits exist for major cities and these discussions can be informative to potential and would-be travelers. Make sure to look up how the frequency bands and phone standards may differ from your country and the country you’re going to.

If your phone can connect to 5G in the other country, you may just need to add international service to your existing phone plan, and check that your carrier has an agreement in the country that you’re visiting. If your carrier doesn’t, then you might need to buy a SIM card and install it while you’re abroad. Alternatively, you might consider buying a phone in that country for use when travelling; remember, Wi-Fi is an international standard, so your phone can still be used with public Wi-Fi where available (as long as you do so securely).

Three apps for (potentially) seamless International calling

Once you’re able to connect to the data networks in the country you’re visiting, Google Voice, Teams, and WhatsApp can simply become your phone service. Each has its pros and cons, but the main concern here is that you be able to call the people that you want and need to by using the right platform. Each is configured slightly differently for how you might use it while abroad.

Google Voice

Of our three choices, Google Voice is the solution that most looks like a phone carrier would. To make international calls with Google Voice, you may need some credits added to your account, for instance, and when you make calls on a cellular network abroad, it will work however your voice calls work with your carrier. For example, to use Google Voice calling in its “regular” mode, you’ll need your plan to support the network you’re connected to.

To make calls over the internet with Google Voice, you’ll turn on “Prefer Wi-Fi and mobile data,” in your app’s settings, and start the call from inside the app. This will use data over your network or Wi-Fi connection to place the call, eliminating the need for call credits or paying per minute, although you will use data (about 0.2 MB per minute) and possibly pay for that through your carrier.


Using WhatsApp for calling when abroad (like the other two apps), doesn’t require you to change your number to a local number or show that you’re in another country in any way. Even if you do buy a local SIM card for use in another country, your WhatsApp number will continue to be the home number of your device.

This is convenient and simple, and requires no changes on your end, but beware that if you need to re-verify this device, you won’t be able to complete it with the new SIM card. This means that you might have to pause use of WhatsApp until you can insert your home SIM card, connect to a network that your carrier can use, and re-verify your number. If that happens, you be able to use the local number of your SIM card to make calls, but depending on whether or not your chat history is backed up, you may lose access to your already existing chats and groups.


Teams meetings (both video and voice) will work as they normally do when you’re abroad. Again, using a mobile device connected to Wi-Fi or a data enabled network will mean that you are using the internet to complete the call, and your data will be charged at its normal rate for data usage on a wireless network. Similarly to WhatsApp, your number doesn’t change just because you’re in another country.

With Teams, the region/country of your 365 license determines what your local number is, and it doesn’t change unless you move your 365 license to another country. Using your Teams phone to make public-switched phone calls (regular phone calls) in the country you are currently in will require an international calling plan that you purchase through your Microsoft license vendor. Depending on which country you’re travelling to, you might be able to purchase a pay-as-you-go plan to make calls to numbers in the area in which you are traveling.

Ultimately, the most straightforward solution is to have your phone connected to the local 5G network, and to understand the costs that you may incur for using your phone in the way that you’re most comfortable. While these three solutions offer the ability to make all the calls you need to back home, calling phone numbers in the area that you’re traveling are mostly treated as international calls from your home region to the area where you are traveling. Internet-based forms of communication like WhatsApp can be a great way to sidestep calling and SMS fees, but still require being connected to the internet and paying for data with a wireless carrier.

-Written by Derek Jeppsen on Behalf of Sean Goss and Crown Computers Team