The Nomad Stack: How We Stay Connected (Phones, Numbers & Data)

After a decade-plus of full-time travel across 120+ countries, Lisa and I have tried pretty much every approach to staying connected by phone. We've been ripped off by roaming charges, locked out of bank accounts, and spent entire mornings at airport kiosks trying to get a SIM card activated in a language we don't speak.

We've also figured it out.

This is our phone stack — the setup we've landed on after years of trial, error, and one memorable incident in Vietnam where I couldn't access our bank account for three days. (More on that in a minute.)

The Phone Itself Barely Matters

Let's get this out of the way first: your phone doesn't matter much. Any modern smartphone that accepts a SIM card — which is basically all of them — will work fine internationally.

That said, there's one thing worth paying attention to.

Get a phone with both an eSIM and a physical SIM slot. Most of the world has moved to eSIMs, and they're great. But physical SIMs are still cheaper in some countries. Vietnam is a perfect example — a physical SIM costs less than an eSIM for the same data. We're talking small amounts of money, and yes, you're a person who's spending thousands on flights and hotels and somehow gets wound up about saving $3 on a SIM card. (I see you. I am you.)

Here's the catch: if you buy your iPhone in the United States, it doesn't have a physical SIM slot anymore. Apple killed it. My most recent iPhone was purchased in Europe specifically because the European models still include one. Is that overkill? Maybe. But having both options has saved me hassle in a handful of countries where eSIMs were either unavailable or overpriced.

A few countries in Africa and parts of Asia still don't offer eSIMs at all. That number shrinks every year, but if your travel plans include off-the-beaten-path destinations, the physical SIM slot is nice insurance.

One more thing: make sure your phone is unlocked. If you bought it outright, you're almost certainly fine. But if you financed it through a carrier or got some kind of promotional deal, there's a chance it's locked to that carrier's network. Check before you leave. Getting locked out of using local SIMs because of a carrier restriction is a completely avoidable problem.

The Two Things Your Phone Needs to Do

International phone use really comes down to two separate problems: voice (can people call you, can you call them, can your bank send you a verification text?) and data (can you get on the internet?). These are different problems with different solutions, and most people mash them together. Let's pull them apart.

Voice: The Problem Nobody Thinks About Until It's a Crisis

Here's the Vietnam story I promised.

I needed to log into our Chase account. Chase wanted to send a two-factor authentication (2FA) code to my phone number. My number was on Google Voice. Chase looked at it, decided it wasn't a "real" phone number, and refused to send the code.

No code, no login. No login, no access to our money.

Three days. That's how long it took to sort out.

This is the thing that will ruin your trip. Not the data. Not the roaming charges. It's the moment your bank, your brokerage, your health insurance portal — any service that uses SMS verification — decides your phone number isn't real enough.

Why Google Voice Fails — And Why It's Unpredictable

Google Voice is VoIP — Voice over Internet Protocol. So are most of the cheap virtual number services marketed to travelers. The number looks like a real phone number. It behaves like one in most situations. But underneath, it routes through the internet rather than the cellular network.

Banks, government agencies, and fraud departments sometimes distinguish between VoIP numbers and real carrier numbers. The mechanism is a set of databases — multiple competing ones, in fact — that categorize phone numbers by type: mobile, landline, VoIP. When an institution goes to send you a verification text, it checks the number against those databases first. If it comes back flagged as VoIP, the text doesn't go out. No error message. No explanation. The text just never arrives.

What's actually happening: the bank's SMS gateway receives an error code flagging the number as VoIP or non-mobile, but the bank doesn't surface that to you — partly for security reasons, partly because it just doesn't.

Here's what makes this genuinely difficult: the databases aren't consistent, and they aren't static. They're continuously updated, and different institutions check different databases. That's why you'll find people in travel forums insisting Google Voice works perfectly for their bank while someone else — same bank, same Google Voice — can't get a code to save their life. They're both right. It depends which database their bank queried that week.

A further wrinkle: Google Voice numbers are often recycled from old landline blocks. A number's history — its previous life as a landline before Google absorbed it — can affect how databases classify it. Two people with Google Voice numbers from different number pools may get different results from the same bank.

It gets more granular than that. Some institutions will send routine messages — balance alerts, marketing — to a VoIP number without issue. But trigger a fraud review, or try to log in from an unfamiliar country, and suddenly a more stringent verification kicks in. VoIP doesn't just fail sometimes — it fails exactly when you're most vulnerable. That's what makes it a real problem rather than an occasional nuisance.

Calls on a VoIP number generally work fine. It's specifically the SMS verification use case where things break down. Worth noting if you're an iPhone user: if most of your contacts are too, you may think your Google Voice number works perfectly for messaging — because iMessage routes over data, not the phone network at all. The problem is standard SMS, which is what banks use. You won't discover the gap until a bank tries to text you.

Google Voice is the one people ask about most because it's free and widely used. But the same issue applies to other inexpensive virtual number services. If it's not a real carrier number — T-Mobile, AT&T, Verizon, or an MVNO that runs on one of those networks — you can't count on receiving all your messages all the time.

The $3–$5/Month Solution — Voice Only

Port your real phone number to Tello or Ultra Mobile PayGo.

Both are real carrier numbers on real mobile networks — not VoIP. Banks recognize them. Verification codes arrive. Your number works.

Ultra Mobile PayGo is the cheaper option at $3/month. You get 100 minutes, 100 texts, and 100MB of data. It runs on the T-Mobile network, same as Tello. The catch: you need to buy a physical SIM card (available on eBay from Ultra's official seller for about $10–$13). No eSIM option for PayGo.

Tello is $5/month and also gives you 100 minutes plus free texts. Tello supports eSIM activation, which is more convenient if you don't want to deal with a physical card.

Critical point that most people miss: Tello and Ultra Mobile are for voice and SMS only when you're abroad. Do not use them for data. Both have data plans that make sense in the U.S., but internationally their data is expensive — priced at rates that will shock you when the bill arrives. This is the trap. People sign up, see that a data plan is available, assume it's part of the deal, and end up paying far more than they should.

The right way to think about Tello or Ultra Mobile abroad: they're piggybacking on your other data connection to keep your U.S. number alive and reachable. Your Tello SIM handles calls and texts. Your data comes from somewhere else entirely — Roamless, a local SIM, whatever you've set up for that. Go into your phone's cellular settings and disable data for the Tello or Ultra Mobile SIM. Leave voice and SMS enabled. That's all it needs to do.

That's it. That's the whole thing.

Port your existing number, pay $3–$5 a month, and you never have to worry about being locked out of a critical account because some fraud-prevention algorithm decided your number looks suspicious.

A note on number porting: When you switch to Tello, Popcorn, or any new carrier, you have the option to port your existing number so you don't have to deal with a new one. Expect to follow a few steps, but it's generally quick and painless — usually done within minutes. That said, porting only makes sense if you're committing to a longer-term setup. It's not worth the effort for a short trip. If you're going nomad for the long haul, port your number before you leave and be done with it.

One important note about activation: If you're already overseas, this gets trickier. Tello has been cracking down on overseas activation — recent reports suggest they may block it, though some people have gotten it to work with a VPN. Ultra Mobile PayGo, on the other hand, has confirmed through customer service that they still allow overseas activation with their physical SIM. Either way, the smart move is to get this set up before you leave the country. Test it. Make sure your bank can text you. Don't figure this out at the airport.

Is $36–$60 a year going to break anyone's travel budget? No. Is it worth the peace of mind of knowing Chase, Schwab, your health insurance company, and every other service that insists on texting you a code will actually be able to reach you?

It's the best money you'll spend all year.

The Case for Google Fi and T-Mobile (For Shorter Trips)

I used Google Fi for a long time. It was great — voice and data, works internationally, reasonable price. T-Mobile is similarly strong: their qualifying plans include unlimited texting and data (albeit throttled to 256kbps on basic plans) in 215+ countries, with calls at $0.25/minute. Their higher-tier plans include 5–15GB of high-speed international data before throttling kicks in. No setup, no SIM swaps, just land and go.

For trips of one to three months, these are genuinely excellent options and probably the simplest path. You don't have to change anything about your plan. You don't have to learn about Tello or Roamless or any of this. Your phone just works when you land, and the price is baked into what you're already paying.

Here's where it falls apart: both services have policies that restrict your international data if you stay outside the country for extended periods. T-Mobile's terms explicitly say the service is "not for extended international use" and they reserve the right to restrict service for excessive roaming. Google Fi has similar limits. I've had my data cut off by both services. They actually enforce this.

People in nomad forums will cite the specific time limits and argue about how strictly they're enforced. Don't waste your energy. The limits exist, and if you're gone for three months or less, you're almost certainly fine. If you're gone longer than that, you're rolling the dice.

The bottom line: If you're already on T-Mobile or Google Fi and you're traveling for a few months, don't change a thing. Use what you have. The Tello/Roamless approach is for people who've blown past those time limits — or who know they will.

The All-In-One Solution: Popcorn

After years of cobbling together separate voice and data solutions, Lisa and I switched to Popcorn. It's $69/month per line. We each have one.

What you get: unlimited voice calls, unlimited texts (including those bank verification codes), unlimited data, coverage in nearly all countries, and you keep your real phone number.

Is $69/month the cheapest option? No. It works out to about $2.30 a day. But here's what I don't do anymore: I don't buy SIM cards at airports. I don't configure eSIMs. I don't wonder if my data will work when I land. I don't worry about whether my bank can reach me.

I land, I turn off airplane mode, and everything works.

For someone who spent years being the guy who knew every trick for saving $4 on a SIM card, I'm now the guy who happily pays for the convenience of not thinking about it. That's what years of travel does to you — it teaches you what's actually worth optimizing and what's just noise.

A Note on Popcorn's Backup eSIMs

Popcorn offers something worth knowing about: backup eSIMs for when their standard connection isn't performing well. Most people never need them and never ask about them. But if you're somewhere with a slow or unreliable connection, they're worth requesting.

Here's the underlying issue. Popcorn is a U.S.-based provider. The data on their standard plan routes through U.S. servers — meaning every packet of information you send or receive has to make a round trip to the U.S. and back. Think of it as every Google search traveling to New York and back before you see a result. That physical distance adds latency. For streaming or video calls in particular, you'll sometimes feel it.

The backup eSIMs fix this by routing through servers closer to where you actually are. For Europe, the server is in the UK. For Asia, it's Singapore. For the U.S., there's a domestic option. Each of these is also more flexible about which carriers it connects to — the U.S. backup eSIM, for instance, can access AT&T, T-Mobile, and Verizon, which means it can find a signal in places where your primary Popcorn connection might be weak.

You have to ask for these; Popcorn doesn't hand them out automatically. Installation takes a few minutes and requires some comfort with eSIM configuration — it's not for everyone. But if you're traveling through Europe or Asia and noticing sluggish data performance, it's worth a call to their support team.

Tower Priority: What It Means and When It Matters

There's a connectivity hierarchy that most people don't know exists — and it only becomes obvious when you're standing somewhere with full bars and your phone can't load a webpage.

When a cell tower gets congested — a stadium, a concert, a massive street festival, an airport at peak hour — carriers have to triage who gets bandwidth. Real customers come first. Postpaid and prepaid subscribers with direct contracts with the carrier get priority access to the network. MVNOs, resellers, and international eSIM services that lease capacity from the big carriers sit below them in the queue.

In practice: if you're at the running of the bulls in Pamplona on a third-party global eSIM — Roamless, Airalo, or any of the services that aggregate international coverage — you may find your data effectively stops working when tens of thousands of other people are trying to use the same tower. The carrier's own customers get served first; you get whatever's left.

For everyday use, this distinction is invisible. The network isn't congested, everyone gets bandwidth, and you never notice the difference. But the moment it matters is exactly the moment you really want your phone to work.

If tower priority is important to you — and it will be, at some events in some places — the answer is to buy a local SIM from the actual carrier, not through a reseller. A local prepaid SIM puts you on equal footing with any other customer on that network.

The Budget Approach: Voice + Data, Handled Separately

If $69/month feels like too much, here's the approach that works and won't leave you stranded.

Step 1: Get your number on Tello or Ultra Mobile PayGo ($3–$5/month). This handles voice and SMS verification. Disable data on this SIM when you're abroad — it's not for data use outside the U.S.

Step 2: Your Tello or Ultra Mobile SIM piggybacks on whatever data connection you set up — a local SIM, Roamless, or anything else. The voice SIM rides along; the data SIM does the heavy lifting.

For physical SIMs, you can usually grab one at the airport or in the city when you arrive. Prices vary, but you're typically looking at $5–$15 for a chunk of data that'll last a few weeks. In Southeast Asia, it's often even cheaper.

For eSIMs, there are dozens of services that'll sell you one online. You buy it before you arrive, follow the setup instructions, and you're connected when you land. I got to the point where I could set one up without thinking about it. Other people find it maddening. You know which one you are.

One thing worth saying about eSIM complaints: most people who tell you "eSIMs don't work" didn't follow the setup instructions. The most common failure is forgetting to turn on data roaming after installation. The eSIM itself is fine. Read the instructions.

The downside of this approach is that if you're moving between countries frequently, you're buying and configuring a new SIM every time you cross a border. That gets old.

The Middle Ground: Roamless

This is the option I wish had existed when I started traveling.

Roamless is a single global eSIM. You set it up once, and it works in 200+ countries. No swapping. No configuring. You cross a border and it just connects.

You pay by the gigabyte — either through their pay-as-you-go option (credits that never expire) or fixed data plans for specific countries. Pricing varies, but you're generally looking at somewhere between $1.25 and $4 per gigabyte depending on the country and plan type.

This fixes the biggest annoyance of the budget approach: constant SIM swapping. And because you're paying for what you actually use, you're not throwing away half a 20-gig SIM card every time you leave a country early.

The catch: Roamless is data-only. No voice, no phone number, no texts. So you'd still want Tello or Ultra Mobile PayGo handling your phone number — piggybacking on Roamless for data wherever you go.

What About Just Keeping Your Verizon/AT&T Plan?

If you're traveling for two weeks? Just do this.

Both Verizon and AT&T offer international day passes for about $12/day. AT&T even caps it — you only pay for the first 10 days per billing cycle, and the rest of the month is free. So a month of AT&T international roaming maxes out at $120.

Everything works exactly like it does at home. No settings to change, no SIMs to buy, no apps to download. Your phone just works.

For a two-week vacation, you're looking at maybe $150 total. Is that worth more than the hassle of setting up a foreign SIM card on what's supposed to be your relaxing holiday? For most people, absolutely.

But for full-time travelers? $120–$360 a month (depending on your carrier) is a lot when better options exist.

The Decision Framework

Here's how to think about this.

Traveling for less than a month? Keep your existing carrier and pay the daily roaming fee. Don't overthink it. Enjoy your trip.

Traveling for 1–3 months? If you're already on T-Mobile or Google Fi, just use your existing plan. This is what those international benefits were designed for, and you're well within the time limits where they won't shut you off. If you're on AT&T or Verizon, you could switch to T-Mobile or Google Fi before your trip, or go the Tello/Ultra Mobile route ($3–$5/month) plus Roamless for data.

Full-time nomad? Popcorn ($69/month) and stop thinking about it. Or if you want to save some money and don't mind a bit more hands-on management: Tello or Ultra Mobile PayGo for voice and SMS, Roamless for data — Tello piggybacking on Roamless wherever you go.

On the tightest possible budget? Tello or Ultra Mobile PayGo ($3–$5/month) plus local SIM cards bought as you go. Cheapest option, most hassle — and remember, Tello is voice and SMS only. Your data comes from the local SIM.

The One Non-Negotiable

Whatever you do, make sure your phone number is a real carrier number — not a VoIP number — when it comes to receiving verification texts. This is not optional. This is not something you can figure out later.

The day your bank needs to verify your identity and can't reach you is the day your trip goes sideways. It happened to me. It'll happen to you.

Tello or Ultra Mobile PayGo. Three to five dollars a month. Just do it.

This is part of our Nomad Stack series, where I document everything we use to live and travel full-time. Got questions about your own phone setup? Drop them in the comments.