My cell phone carrier is US Mobile. It costs me $11.48 per month for unlimited talk + text and 1 GB data, and it’s a Verizon MVNO that actually uses their high-priority data line. (Previously, I used prepaid Verizon which was lower-priority.) That’s great for domestic use, but the carrier does not yet support international roaming. The customer support is pretty good too. By the way, if you’re interested, here’s my invite code… https://www.usmobile.com/referrals?referrer=A562A82F

When I traveled to Asia in 2017 and before, I would always use a portable WiFi unit and VoIP services such a Facebook Messenger, LINE, etc. I don’t know why my relatives in Asia always had a portable WiFi unit ready; nobody in the states does. This gets a bit complicated when American business enters the picture, however. My mother contacts the vast majority of her property management clients and tenants through SMS and iMessage.

Enter WiFi Calling. Many modern phones now have WiFi Calling capability: the call will route through the internet to a cell tower. This is useful in areas of low cell service but readily available WiFi (think rural). For us, this is also useful internationally. With a portable WiFi unit, we can continue using our phones as usual, keeping our local number and making local calls without international charges. This is made even more convenient with widespread dual sim: obtain an international 2nd sim (physical or esim) and your cell connection appears uninterrupted and identical to the outside world.

For Android users, this works mostly seamlessly (more on this later). However, iPhone users will find complications with iMessage. Once Airplane Mode is turned on and off, or that particular line is turned off and on in any other way, iMessage does some sort of check to re-activate itself. It requires cell tower connection from the original line and cannot activate through WiFi. What this means is, if you turn your cell line off internationally, you’ll be devoid of iMessage until you return to your home country. Or you’ll need to pay international roaming charges (if available) to get it back.

Now why would you ever turn off your original cell line? Turns out that keeping it on means it keeps searching for nearby towers in the background. There is no way to turn off this functionality, and it drains a lot of battery. I mean, a lot. It comes out to about 40% of my battery per day. This is fine, as I don’t use my phone till it’s empty very much. But I more or less can’t use it except for calling and texting, and I always defer to other phones for navigation. (My battery is around 1811 MAh, while my mother’s is 4500.) I’m kind of confused about this, but no cell coverage also takes up about 40% of my mother’s battery per day. With a bigger battery, I would expect the percentage to be smaller. Without the need to take calls and texts by number, it’s a no-brainer to turn this off. One might as well operate on a data-only plan at home at that point.

Beeper recently released an app called Beeper Mini that gives phone number iMessage access to Android users. It doesn’t use a Mac Mini server farm, either. It’s been a cat-and-mouse race between Apple and Beeper since release. They really hate the idea of reverse-engineered, Android-available iMessage. It means that desktop iMessage is in people’s future, too. I can see a use case for Beeper Mini on iPhones to access iMessage internationally, too, but I don’t think the Beeper team has their sights set on that. I also don’t know if it activates the same way anyways; the source code is on GitHub but I don’t want to comb through it badly enough.

My personal experience: I set this up with mine and my mother’s phone. My international eSIM carrier was DENT, while I used Airalo for the mother. DENT has low prices, but the availability in my current region (China) is disappointingly low. I don’t really know why, I guess the carrier they partnered with was cheap too. My mom’s phone gets much better coverage. Taiwan coverage is fine with both carriers. The reason I chose DENT was because their data is valid for one year. I actually originally purchased this data for a Canada trip in the summer, and I’m still using the same 8-dollars-for-one-GB now. It’s available worldwide, too. DENT has a bunch of weird stuff like reselling your data on the market, watching ads for small amounts of their in-app currency (or crypto) called DENT, etc. It is too odd for me to recommend professionally. I keep DENT on my phone because in the states, it uses both T-Mobile and AT&T networks. As a Verizon MVNO, these three added together basically give me maximal coverage across the country. All this is available for much cheaper than traditional primary cell line data roaming. (I can recommend Airalo, just don’t forget to turn on Data Roaming in the line’s settings page. This is not necessary on DENT.)

This method may or may not work with other carriers. Verizon undesirably charges $10 per day for roaming. I tried setting it up with just Verizon in the past and for some reason, one could receive calls and not make them. Maybe Verizon is aware of this workaround and blocked it.