What is an eSIM and how does it work?
An eSIM is a digital SIM card integrated into your phone: instead of inserting a physical chip, you download a profile with your line's data and the device connects to a mobile network. It works just like a traditional SIM for browsing, but it doesn't take up the physical tray and can't be lost or bent.
The technology isn't new: most mid-range and high-end phones manufactured since 2020 already come with the eSIM chip soldered to the board. What changes is how it's activated. Instead of a store giving you a plastic card, the operator—or the travel eSIM company—gives you a QR code or a link. You scan that code with your phone's camera, the operating system downloads the network profile, and in a few minutes you have a working data line, without opening the tray or touching the phone from the outside.
For travelers, this solves a very specific problem: arriving in another country and needing mobile data without waiting in line at a phone counter or looking for a store that sells chips to foreigners. The eSIM can be purchased and set up before leaving home.
How is it different from a physical SIM?
The main difference is that an eSIM is not an object that goes in and out of your phone: it's information recorded on a chip that is already integrated into the device. This has practical consequences. With a physical SIM, you need the card, a paperclip or tool to open the tray, and care not to lose it when changing it. With an eSIM, the entire process happens on the screen: you scan a code, confirm, and that's it.
How multiple lines are managed also changes. Many current phones allow you to save several eSIM profiles at the same time (although only one or two active ones depending on the model), so you can have your personal line and a travel data line coexisting on the same device without removing or storing any card.
If you want to delve deeper into the technical and daily use differences, there is a complete comparison in SIM vs. eSIM and another focused on when each is convenient in eSIM vs. physical SIM.
A concrete example: traveling to Mexico with an eSIM
Imagine a five-day trip from Bogotá to Mexico City, with a flight arriving at night. The week before the trip, from your home Wi-Fi, you buy a data eSIM for Mexico, scan the QR code, and your phone installs the profile. You don't activate it yet: it just remains saved.
On the day of the flight, as soon as the plane lands and your phone searches for a network, you activate the data line from the settings. In a couple of minutes you have internet: a map to order a taxi, WhatsApp to let people know you've arrived, your hotel reservation at hand. Your usual number still receives calls and SMS through the physical or main line, because the eSIM is added, it doesn't replace that line.
An eSIM does not replace your personal number: it coexists with it. That's why you continue to receive calls and messages with your usual chip while browsing with data via the eSIM.
During the five days you use data normally—maps, social media, video calls—without worrying about roaming charges from your original operator, because that data is being used by the local travel line, not your home plan.
Which company offers eSIM in Mexico?
In Mexico, the major local operators—Telcel, AT&T Mexico, and Movistar Mexico—already offer eSIM for contract or prepaid lines, but to activate them you normally need procedures specific to each country: local identification, sometimes an address, and in some cases, going to a physical store. This process is designed for residents, not for someone visiting for a few days.
The alternative for those just passing through is an international data eSIM, like PuraSIM's, which does not depend on any particular Mexican operator or require a contract: it is purchased online, installed before traveling, and provides access to mobile data as soon as you land, using the local partner network in the destination country.
Which companies offer eSIM cards for travel?
There are two types of companies that offer eSIMs, and it is useful to distinguish them because they solve different problems. On one hand, there are the traditional mobile operators in each country, who issue eSIMs for their own local customers with a number and contract in that country. On the other hand, there are companies specialized in travel eSIMs, which sell international data profiles designed specifically for tourists and business travelers, without requiring residency or a contract.
PuraSIM belongs to this second group: it is a data eSIM for travel, with coverage in more than 200 destinations, which is activated before leaving home and does not require local operator procedures. The difference compared to a traditional operator is precisely that: you don't compete for a spot in a store or depend on business hours, because the installation is done from your phone at any time.
You can see the full catalog of available countries and plans in the international eSIM collection.
What is the disadvantage of eSIM?
No technology is perfect, and it's worth stating clearly before you discover it halfway through your trip. The first limitation is compatibility: not all phones have an eSIM chip, especially low-end models or those unlocked from markets where eSIM is not yet standard. If your phone doesn't support it, no eSIM in the world will work on it.
The second is that, unlike a physical card, you can't take an eSIM out of one phone and put it into another just by moving a chip: if you change devices, you usually have to reinstall the profile, and some profiles only allow one installation. The third is that installing an eSIM requires an internet connection at that moment—Wi-Fi or data from another line—because the profile is downloaded, not delivered by physical mail. And the fourth, more operational: if you factory reset your phone without backing up, you could lose the installed profile and need a new one.
None of this is a reason to rule out eSIM, but it is a reason to plan a little in advance, especially the installation part with Wi-Fi available.
Is my phone compatible with eSIM?
Compatibility depends on the exact model and, in some cases, whether the phone is unlocked or tied to an operator that blocked the feature by contract. The most reliable way to find out is to check your phone's settings to see if there is an option to "add mobile plan" or "add eSIM" within the network menu, or consult the specific model.
There is a detailed list of compatible devices, updated by brand and model, in eSIM-compatible phones. It is advisable to check it before buying, especially if the phone is more than three or four years old.
How is an eSIM installed and activated?
The process is the same in the vast majority of cases, regardless of the phone brand: you buy the eSIM online, receive a QR code (or a link that generates that code), open your phone's network settings, choose the option to add a line or plan, and scan the code with the camera. The system downloads the profile, asks you to confirm the line name, and within minutes, the line is installed.
With PuraSIM, this entire purchase-to-installation process takes about 1 minute once you have the code, and there's no need to activate it immediately: you can install it with Wi-Fi days before your trip and leave it ready, then activate the data once you arrive at your destination. In fact, since there are 180 days to activate the eSIM from the moment of purchase, there's no rush: you can buy it weeks in advance without it expiring before your trip.
The complete step-by-step guide, with screenshots for each operating system, is available in how to install an eSIM. And if something doesn't work as expected—profile not appearing, data not loading—there are solutions to common problems in common eSIM issues.
Travel eSIM vs. roaming: which is better?
International roaming is the service that your own home operator activates so that your line works abroad, usually with an additional charge that varies by operator and destination. A travel eSIM, on the other hand, is a new and separate data line, contracted specifically for that country or region, that coexists with your main number without affecting it.
| Aspect | Home operator roaming | Travel eSIM |
|---|---|---|
| Who activates it | Your usual operator, from your country | You, from your phone |
| Number used | Your usual number | A separate data line; your number remains active for calls/SMS |
| Coverage | Depends on your operator's agreements with that country | Depends on the eSIM provider's destination catalog |
| When to contract | Before traveling, with your own operator | Before or during the trip, online |
| Cost control | Variable; it's advisable to confirm the charge with your operator before leaving | A defined data plan is purchased in advance |
Neither option is "bad" in the abstract: it depends on the trip. A weekend crossing a land border can be resolved with roaming if your operator offers it at no extra cost. A multi-country or multi-week trip is usually simpler with a dedicated eSIM, because it does not depend on an agreement between operators or coverage zones beyond your control. The complete comparison, with more use cases, is in eSIM vs. roaming.
| Aspect | Physical SIM | eSIM |
|---|---|---|
| Delivery method | Plastic card, picked up or mailed | Digital QR code, installed from the phone |
| Risk of loss | Can be lost, bent, or damaged | Does not exist as a physical object |
| Switching between phones | Removed from one device and inserted into another | Requires reinstalling the profile on the new device |
| Where to get it | Physical store, airport, counter | Online, from anywhere with Wi-Fi |
| Compatibility | Practically all phones | Only devices with an eSIM chip (most recent mid-range/high-end) |
Frequently Asked Questions
Do I need Wi-Fi to install the eSIM?
Yes, to install the profile you need an internet connection—Wi-Fi or data from another line—because it is downloaded at that moment. That's why it's advisable to install it before traveling, using home Wi-Fi, and activate it once you reach your destination.
Can I use two eSIMs (or eSIM and physical SIM) at the same time?
It depends on the phone model. Many recent devices allow you to save multiple profiles and have two lines active at once, one physical and one eSIM, or two eSIMs. It's advisable to check the technical specifications of your specific model.
Does the eSIM change my phone number?
No. A travel eSIM is an additional data line. Your main number continues to function for calls and messages through your usual line, unless you decide to use it for that as well.
What happens if I lose or change my phone?
If you change devices, you usually have to reinstall the profile on the new phone. Some eSIM profiles only allow one installation, so it's advisable to check the provider's policy before reinstalling.
Can I share my eSIM data with another device (hotspot)?
On most phones, yes, using the hotspot or internet sharing feature of the device itself, just as you would with any data line.
Do I need an unlocked phone to use an eSIM?
If the phone is locked to a specific operator, that lock may also prevent installing eSIM profiles from other providers. It's advisable to confirm this before purchasing.
Does the eSIM work for calls and SMS, or only for data?
It depends on the provider. Many travel eSIMs, including PuraSIM's, are designed specifically for mobile data, which is what is most used when traveling thanks to apps like WhatsApp for calls and messages.
Conclusion
eSIM is not a complicated technology exclusive to luxury phones: it is, in essence, a simpler way to have mobile data in another country without looking for a store, without a physical card, and without relying on your home operator's roaming. For someone traveling for a few days or weeks, the practical advantage is clear: it is purchased online, installed with Wi-Fi before leaving, and ready to be activated as soon as you land.
If it's your first time using one, the best starting point is to check if your phone is compatible and then follow the step-by-step installation: the definitive guide to eSIM for travel gathers all of that in one place. And when you want to see the available destinations and choose the data plan for your next trip, PuraSIM's international eSIM collection has coverage in more than 200 destinations, with 24/7 support in all languages by email and WhatsApp if anything is unclear during installation.
