What is eSIM? Here’s everything you need to know


By Heather

Travel & Tech Writer


What is ‘eSIM’ and what makes it so useful, especially for travel? Well, there’s a ton of information out there about this magical new technology, so today we’re doing a deep-dive into everything you need to know.

From what is eSIM, how it works, how much it costs, how it can actually save you money, why you should give it a chance, and whether your phone is already eSIM compatible, let’s get started answering all of your eSIM questions …

First up, what is eSIM?

«eSIM» stands for «Embedded SIM,» and it’s the digital version of traditional plastic SIM cards. An eSIM allows your device to connect to different networks. Because they’re digital, there’s nothing to swap out or replace. New eSIM connections can be purchased, installed, and activated on a device from anywhere, without needing to visit a mobile store or kiosk.

What’s the difference between a SIM card and eSIM?

You’ve probably seen a SIM card before, if you’ve switched phone providers and watched them poke a tiny pinhole in your device and swap out the cards. A SIM is what allows a device to connect to a network. If you take the SIM card out of a phone, it can’t make or receive phone calls — or send texts — and if you want to do anything online, you’d need Wi-Fi.

Well, an eSIM works exactly like a traditional SIM card — giving you access to different networks, and keeping you online without needing Wi-Fi. But an eSIM is different because it’s not a physical item. You don’t need to go into a store to buy an eSIM. You can purchase an eSIM data package online (through eSIM retailers like aloSIM), and easily add more data anytime you want.

And unlike monthly data plans with mobile carriers, where you pay for the same amount of data each month, aloSIM lets you purchase short-term data packages anytime — with no commitments or contracts. Just pay for a few gigs here and there, as needed, for local or international travel.

How do I know if my phone has eSIM?

Does your phone have eSIM? Well, many newer-model phones are automatically equipped with eSIM technology and ready to use eSIM data plans. We keep a complete list of eSIM-compatible devices here, updated regularly, so can check to see if your device is supported. (It includes every iPhone from XR onward, and many different models of Samsung Galaxy phonesGoogle Pixel phones, and other phones and tablets.)

Can other devices get eSIM data?

Absolutely! Our list of eSIM-compatible devices includes iPads, Samsung tablets, MANY other tablets, and gadgets from ASUS, ACER, Dell, HP, Lenovo, and Microsoft. Many aloSIM customers enjoy being able to buy temporary data for their iPads, tablets, or computers so they can stay connected while traveling without having to rely on Wi-Fi.

Where can I buy an eSIM?

While some retailers sell eSIM data plans in-store, they’re essentially just packaging up an activation code so they can put it on display as if it were a physical product (and it’s not.)

Here at aloSIM, we prefer the 24/7 convenience of an online eSIM marketplace! Our customers can browse eSIM data plans anytime, compare prices, make a purchase, and install their eSIM right on their device — all within seconds.

What is eSIM useful for?

There are three main reasons people purchase eSIM data plans:

1. Affordable local travel data: They’re traveling outside of their usual coverage zone, and they want to be able to connect to a local network so they can avoid roaming charges.

2. Short-term data for devices that don’t normally have it: An eSIM data plan allows you to put temporary data on a device that might not normally have a network connection, like an iPad or an older phone you no longer use. (Some aloSIM customers like to put a few days’ worth of data onto an old iPhone and send it with their child if they’re going away for a few days, so they can always keep in touch with them.)

3. Prepaid data for people who don’t want a monthly data plan: Not everyone wants to pay $40, $50, or even $60 a month for a cell phone plan. People sometimes prefer a prepaid model, where they can buy data as they need it, without being tied down with monthly contracts and commitments.

While all three of the above are valid reasons to use prepaid eSIM data, the overwhelming majority of our customers are coming to aloSIM for travel data. What can we say? The freedom of never paying roaming charges again is just so, so awesome.

Which is better for travel? eSIM or SIM card?

Back in old days (a.k.a. not that long ago at all), savvy travelers like to «SIM card swap» when they were visiting new places. They’d pop out their regular SIM card and switch it with a local SIM card, usually bought at the airport of their destination.

Now, switching SIM cards might mean the person didn’t pay roaming charges — because the local SIM card provided local data — but removing their regular SIM card also removed every trace of their regular phone number. That meant they couldn’t make calls or receive calls (or texts) for their entire trip.

Not everyone felt comfortable doing this, too, because they may not speak the language in another country and struggle to understand exactly what they’d be purchasing from a vendor. (And, let’s face it, no one wants to mess up their phone by sticking a random card inside it to see what would happen.)

Once eSIMs were introduced, travel communication suddenly became a lot easier.

These days, travelers can shop online for eSIM travel data packages, compare coverage options, and decide which plan makes the most sense for their trip. They can purchase an eSIM plan before they leave on their trip, and get it all ready to go, so that once they arrive at their destination, all they have to do is activate it and POOF! They’re connected to a new local network.

Because eSIM users don’t have to mess around with physical SIM cards — no swapping, no risking losing or damaging your primary SIM card — they can easily bounce between plans, or even use both plans at once.

Many phones and tablets allow for dual SIM technology, so you can keep your primary SIM (regular phone line) «on» while you’re using your travel eSIM (for local data) also «on.» This means you can still make/receive phone calls and texts on your real number while you’re away, but you’re not acruing roaming charges because you’re only using your travel eSIM for roaming data. (More details on that in this post.)

When you’re back from your trip, it takes seconds to flip back to your primary SIM. No need to open up your phone, swap any cards, or visit your mobile provider. Just a few screen taps is all it takes!

How does eSIM prevent roaming charges?

Great question! «Roaming» is the scary mobile term that a lot of people don’t fully understand, and its uncertainty is what makes it so nerve-wracking.

For starters, if you have a cell phone plan with a provider, you are paying for cell coverage within a certain area. Maybe this is your state or province, or maybe it’s your whole country. Whatever your coverage area is, you’re entitled to call/text/browse using that data within that specific coverage area, with no problems.

But if you LEAVE your coverage area, that’s when things can get dicey. Your cell phone provider doesn’t want to be keeping your device connected when you’re halfway across the world (or even just barely across the border), so they’re going to charge you for the luxury of staying connected outside of their zone.

This is roaming. (Better known as «Your phone’s not at home anymore, so be prepared to pay up if you want to use it.»)

So let’s say you leave your coverage area anyway (without any prior arrangements because you’re a rebel that way). You might see a message pop up from your provider warning you that you are «now roaming» and can expect to pay X in roaming charges.

If you let your device «roam,» then your provider is going to keep careful track of every second it has to keep you connected while you’re outside their coverage zone. Every speck of data needs to be paid for, and the data is expensive because you’re no longer close to home. Even if your device is searching for a connection to do something dumb — like update your apps in the background — your carrier is tracking the data is takes, and you’ll see it ALL add up on your next bill.

The idea of roaming sometimes freaks people out, and they just switch off their phone entirely (or put it on Airplane Mode) for the rest of the trip. But that’s where travel eSIM plans are so helpful!

Before you leave on your trip — or as soon as you arrive, if you’re a fly-by-the-seat-of-your-pants kinda traveler — you can browse affordable eSIM travel data packages and choose the one that makes sense for your trip. Install it and activate it within seconds, and then you have access to low-cost, LOCAL data for the country or region you’ll be visiting.

So how does this prevent roaming charges? Well, now that you have local data, you can use that for roaming instead. You’ll switch roaming «off» on your primary SIM, and switch roaming «on» on your travel eSIM. That means you’ll stay connected just as if you were a local to that particular area. Pretty fantastic, right?

Oh, and you can also choose to keep your primary SIM active, if you’d like to be able to call/text on your usual number while you’re traveling. While your usual mobile carrier will charge you for individual calls (per airtime minute) and texts, it’s usually pretty cheap. (Check with them to confirm pricing, as each carrier is different.)

If you don’t mind paying a few bucks for the odd phone call or text, you might consider it well worth it for the ability to stay fully connected and reachable on your main phone number while you’re traveling. (Some of our customers appreciate that if there’s an emergency back home, they can be contacted immediately on the number everyone already knows.)

Roaming charges are the big-ticket item, and if you’re using a local eSIM for all mobile data needs, then you’re all set!

What is eSIM travel data?

Well, travel data is how you can stay connected when you’re traveling outside of your usual coverage zone. It’s much cheaper than roaming because you’re tagging onto a local mobile carrier for data instead.

Before you leave on your trip, you can talk to your mobile carrier about eSIM travel data plans, or you can shop for lower travel data rates with an eSIM retailer.

Should I use an eSIM travel data plan, or a carrier travel data plan?

Most carriers do offer travel data plans, but sometimes they’re quite expensive. You might pay $20 a day for a carrier travel plan, whether you use your phone much or not. Yikes! If you want to talk to your carrier prior to your trip, there are a few important questions you should ask about travel data so you that understand the carrier’s rates, restrictions, and what you can expect on your next bill.

But if you find your carrier’s travel data rates high, don’t worry! You have another option: an eSIM travel data plan. This means that instead of relying on your carrier for travel data, you shop for your own plan, activate it right on your device, and use that for travel data instead.

eSIM data plans are usually much cheaper than what your carrier can offer because you can customize the amount of data you buy, and how long you need the package to last. If you want to stay connected for the cheapest possible amount, you can buy a single gig of local data and stretch it out for your whole trip. It’s totally up to you!

So when it comes to deciding whether to use carrier travel data or eSIM travel data, we think eSIM travel data is the clear winner.

How much travel data do I need?

The amount of travel data you need depends on where you’ll be visiting (how’s the Wi-Fi?), how connected you want be (unplugged and chill, or always reachable), and how you plan to use your data (mostly just checking your socials, or full-out communication via calls, texts, video chats, you name it).

Of course, it’s harder to pinpoint exactly how many gigs of data you’ll need, because everyone uses their device differently. That’s why an eSIM travel data plan can be super convenient.

You could start off with a small package (maybe even just 1 GB of data), and see how it goes. If you’re on Wi-Fi for much of the trip, or you’re not really using your phone very much, that single gig of data could be all you need. But if you happen to use it up and want some more, it’s easy to top up an eSIM package with additional data.

Unlike carrier travel data packages (that might be way more than you’ll ever need), aloSIM eSIM data plans are low-cost, flexible, and commitment-free, so you’re free to start small and test the waters.

How do I get an eSIM travel data plan?

Don’t get off the couch, because it’s easy to shop for eSIM data plans online. Here at aloSIM, for example, you just search by country (or by region), choose the location where you need data, and browse available eSIM data plans. When you find a data package that works for you, it takes seconds to install and activate it right on your device.

What is eSIM’s cost? How much are eSIM data plans?

eSIM is free to activate, since the technology already exists on most of our devices. (Here’s a handy list if you want to check to make sure your phone or tablet is eSIM-compatible.) But you’ll pay for individual eSIM data plans, based on how much data you need, how long you want to use that data, and the average cost of mobile data in a particular area. (Some areas are much more expensive than others, simply because of infrastructure.)

The nice thing about eSIM data packages is that it’s easy to browse around and choose a package that will suit your needs, whether it’s 1 GB for three days for a long weekend away, or 10 GB for 30 days if you’re working abroad for a month. Here at aloSIM, for example, you just search by country (or by region), choose the location where you need data, and browse available eSIM data plans.

How often am I charged for an eSIM data plan?

We can’t speak for our competitors, but here at aloSIM, our customers only pay for individual data plans as needed. No contracts, no commitments, and no reoccurring charges ever.

Buy a data plan, and we’ll let you know when it’s about to expire (due to time or data allowance). If you don’t want to top it up, that’s no problem at all. Just let it run out. We’ll never charge your cards behind your back. We believe in an affordable prepaid mobile data system, where people can secure the data they need without accidentally purchasing anything else.

Do all eSIMs come with phone numbers?

No, not all eSIMs come with phone numbers. Many eSIMs are «data-only eSIMs,» which means they provide cellular data but not an associated telephone number. This is because people often just want eSIMs for data purposes — they either already have a phone number (or several), and aren’t interested in getting another one. Which brings us to our next question …

How do I make phone calls using a data-only eSIM?

Making phone calls with a data-only eSIM is easy! In fact, there are three easy methods:

1. Making calls using an app.

Secondary phone number apps like Hushed (our sister app) provide virtual phone numbers in 300+ area codes, so you can easily talk, text, accept voicemails, etc. all using a temporary phone number that works anywhere there’s Wi-Fi or data. Other options for making calls with a data-only eSIM include WhatsApp, Zoom, FaceTime, Skype, etc.

2. Making calls over social media.

Facebook and Instagram both have calling features, so you can easily organize a video call with your contacts there.

3. Making calls using your real phone number (carrier charges apply).

If you want to remain fully connected while you’re traveling, you can rely on your data-only eSIM for a strong data connection (with no roaming charges) and keep your primary SIM switched on for calls and texts.

Your primary carrier will not charge you for roaming (providing you have roaming turned off for that SIM, and only use your eSIM for roaming), but they will charge you for individual messages sent, and well as airtime minutes spent on a call. The extra fees will appear on your next bill, and may not amount to much. (But it’s best to ask your carrier beforehand so you’re not surprised when you see the bill.)

But since your carrier can’t charge you for roaming (you’re using eSIM travel data for that), and they’ll only charge you for phone calls you actually answer, you could always glance at your screen, see who’s calling, and then reach out to them on another (free) channel. (Sort of like back in the payphone days, where your parents would get a collect call from HiMomPickMeUpAt5, and just decline the call because they’d already gotten the message.)

With an eSIM, do I have access to my regular phone number?

Absolutely! As long as you keep your device supports dual SIM (two SIMs) and you leave your primary SIM switched on, you’ll have full access to your regular phone number while you’re using an eSIM. As mentioned above, remember that your primary mobile carrier will charge you for calls/texts that occur outside of your usual coverage area — but roaming is the big expense, and you’ll be avoiding that by using an eSIM for data instead.


Whew! That’s a lot of information all about eSIMs, so if you’re still reading, you deserve a sticker and a personal pan pizza, like we used to get back in elementary school for hitting our reading goals 😉