We’re not talking about what happens when, in rage, you throw your phone across the room. Rather, what’s worth considering when traveling outside your home area to a domestic or international location where your primary cellular carrier lacks service?

Over the last few weeks, I have been helping my parents and others navigate the choices of cellular service providers when preparing to travel, as well as coaching them on some important steps to ensure functionality while away. There are a few important considerations.

I previously wrote about this topic in Taking iPhone Abroad, which was not as exhaustive a look at options as today’s post. However, I’ve since updated that article with a bit more detail.

Wi-Fi vs. Cellular

As a foundation, it’s important to understand the difference between Cellular and Wi-Fi. Wi-Fi is your ability to connect to the Internet over a wireless network served pretty close to where you are. You manually connect to such a network by choosing its name and either entering a password or being granted access.

Apart from your home Internet service, Wi-Fi generally doesn’t incur a separate fee by venues that offer it. Instead, the cost is baked into other purchases, such as food or drink at a café, or a hotel reservation.

More on Cellular

The other way you access services via a mobile phone (and occasionally a tablet) is Cellular. This comes in two flavors. When you have a phone number, Cellular offers phone and text messaging services, commonly branded “talk & text.” For general Internet access, including most of the applications you use on your device, you have a Cellular Data plan. The cost of cellular and cellular data plans can vary widely depending on where you shop.

Finally, it’s worth noting that cellular services operate with support from a SIM, which can be a physical card or a digital service. Modern iPhones offered since fall 2018 support dual-SIM operation, where a physical SIM and an eSIM (iPhone 13 and earlier) or two eSIMs (iPhone 13 and later) simultaneously provide cellular service.

Note: In this article, “primary” refers to the cellular number/plan you use at home and “secondary” is the line you’ve added for access while traveling.

Staying Connected While Away

When traveling to an area where your cellular carrier doesn’t offer service, you can rely exclusively on Wi-Fi, add another service provider, or, if traveling abroad and your carrier offers one, choose an international add-on plan.

In a cellular dead zone, Wi-Fi may be your only option. On the flip side, when traveling internationally, unless you’re going on a cruise and will be on the ship the whole time, relying only on Wi-Fi more than likely won’t work for you.

An international plan, such as those offered by Verizon, AT&T, and T-Mobile, can be costly if you are trying to conserve funds or are going on an extended trip. These are add-ons to your domestic service plan. BestPhonePlans outlines some choices, though may not be up to date.

However, this gives you a convenient way to retain access to your primary phone number (to make and receive calls and texts) and avoids the need to jump through hoops to use that line when on another carrier’s network.

In truth, if you’re pretty savvy with technology these hoops could be river rocks that support you on your way. If you’d rather not be bothered to monitor your reception and usage, they could be stalagmites that you trip over while spelunking in the dark.

Whether traveling domestically or internationally, you may instead choose to get a cellular plan with a local or regional carrier that provides service in the place(s) you’ll be. If a carrier serves all the places on your itinerary, you can choose a cellular plan from the one provider. Otherwise, there are regional and global plans available that can roam onto a different network in each locale.

An eSIM to Keep You Online

If you choose a third-party cellular plan and you want to get set up before your trip, I recommend those offered by Nomad or Airalo. You can install the app on your smartphone, find a plan that satisfies your needs and will work in the place(s) you’re traveling, and activate service with an eSIM.

If you prefer, you can seek out the provider of your choice using sites like esimdb and esims.io. For reference, the latter lists the cellular networks supported by each plan.

When I got married at River’s Bend Retreat Center, a Verizon dead zone where AT&T service is reliable, esims.io led me to Nomad, whose United States plan supports AT&T, Verizon, and T-Mobile.

When You Arrive

An alternative is to wait until you arrive at your destination and visit a cellular kiosk (in the airport, for example) to get an eSIM for service during your visit. This might get you a cheaper data plan but won’t necessarily work if you are traveling to a variety of destinations.

Additionally, if upon arrival you need to be reachable at a previously known phone number, you’ll either need to be connected to Wi-Fi right away or you’ll need a plan that works when you fall out of the sky, as it were, and to know how to activate it upon touchdown.

The next question is how much data to get. There are a variety of calculators online that attempt to help you answer this question. If you will be a tourist looking up information, getting directions, uploading and posting photos, and making and receiving phone calls using your primary number, you may need 10–20GB per month.

Once you have the plan you want, follow the instructions from the provider to set it up on your phone. When you reach your destination, make sure to enable Cellular Data on the new line.

Wi-Fi Calling with Wi-Fi or Cellular Data

When using a third-party cellular service and wanting to retain access to your primary number — for making and receiving calls and SMS text messages — when its carrier doesn’t have service, the line must have Wi-Fi Calling enabled.

You’ll find this in Settings > Cellular > [primary line]. This will provide it service while your phone is connected to a wireless network. But what about when it isn’t?

There’s a hidden capability where Wi-Fi Calling operates over the Cellular Data of a working line. The terminology is kind of a misnomer since it’s not actually Wi-Fi; that’s just what the feature is called.

This feature, which became available as of iOS 13, is poorly documented by Apple and cellular providers, but I’ve found a reasonable explanation in the “recommended” response of this discussion. There are four prerequisites for this to work:

  1. The primary line does not have service
  2. The secondary line does have service
  3. Wi-Fi is enabled
  4. The phone is not connected to a wireless network

The one other trick here is that this feature won’t work if you have just disabled Airplane Mode. To reactivate, go to cellular settings, switch off your primary line, and then switch it back on. If you have met the prerequisites above, within 10 seconds you will see that your primary line is using the cellular data of your secondary line.

A Few Other Tips

1. The instructions for your travel line may indicate that Data Roaming must be enabled. However, if you’re staying put in a place served by a single carrier, you may be able to conserve battery by disabling Data Roaming and specifying the carrier.

In Settings > Cellular > [secondary line] > Network Selection, disable Automatic. Wait patiently while your provider fetches a list of available carriers. Then, select one you know works in your location. Also, disable Data Roaming.
2. Your phone will use a fair amount of power for all of your Internet activities while on cellular. Thus, you may benefit from keeping Low Power Mode active most of the time. iPhone will disable Low Power Mode when charging the battery reaches 80%, however you can use a Personal Automation shortcut to reenable Low Power Mode.
 
3. To further reduce cellular usage and battery depletion, consider enabling Low Data Mode in Settings > Cellular > [secondary line]. If you’re on a poor Wi-Fi connection, you can also enable Low Data Mode for the Wi-Fi network in Settings > Wi-Fi > [Wi-Fi network name].

Does the engagement of a third-party service sound overwhelming or too complicated? I agree there’s a lot to it. You may want to be — or travel with — someone savvy enough to dance through these aforementioned hoops.

However, while I think you could get into a practice that makes it work for you, and I think it might be less expensive overall, you might prefer a simpler route. If so, you have a couple options:

  1. Have a primary carrier that offers an international plan and pay the premium for it
  2. When you reach your destination, get a data plan that comes with a phone number and don’t rely on your primary number during your travels (but maybe have it available as needed)

Let me know if you need more help weighing the options and deciding how to move forward. Plus, what other electronics are you taking on your adventure? Feel free to share tips from your own travel experiences as well.