What Is an eSIM and How Does It Work | Complete Guide 2026

You've heard about eSIMs, you see more and more travelers using them, but you're not sure exactly what one is or whether it's right for you. Maybe you're worried it's complicated, that it won't work on your phone, or you simply don't understand how it replaces the traditional SIM card you've always used.

Relax—you're in the right place. In this guide I'll explain everything you need to know about eSIMs in a clear, practical way, so you can decide whether it's the best option for your next trip.

What exactly is an eSIM?

An eSIM (embedded SIM) is a digital SIM card that comes built into your mobile device straight from the factory. Unlike traditional physical SIMs, which are plastic cards you insert into a slot, an eSIM is a chip soldered to your phone's motherboard that can be reprogrammed with different data plans.

Think of it this way: the physical SIM is like a key you insert and remove by hand. The eSIM is like a smart lock you can reprogram remotely without changing anything physical. Your iPhone, Samsung, or Google Pixel already has this chip built in—you just need to activate it with your provider's data.

eSIM technology was developed by the GSMA (the global association of mobile operators) and launched commercially in 2016. Since then, it has become the standard for modern devices, especially in the premium segment.

How does an eSIM work technically?

The eSIM chip vs the physical SIM

Traditional physical SIM:

• It's a removable plastic card (nano-SIM in most modern phones)
• It contains a chip with your phone number and account data
• You have to physically insert it into a slot on the device
• To switch carriers, you need to get a new physical card

Built-in eSIM:

• It's an MFF2 (Machine Form Factor 2) chip permanently soldered to the device
• It measures approximately 6mm x 5mm x 0.6mm (much smaller than a nano-SIM)
• It can store multiple carrier profiles at the same time
• It's activated with a QR code or a direct download from the provider

The activation process

When you buy an eSIM from a provider like NAVEO, the technical process works like this:

1. Profile generation: The provider creates a digital profile with your plan details (country, GB, duration)
2. Activation code: You receive a unique QR code or an activation code by email
3. Profile download: Your phone downloads the eSIM profile from the provider's servers
4. Automatic activation: The eSIM chip is programmed with your new plan's data
5. Network connection: Your device automatically connects to the associated local networks

The whole process takes 2-5 minutes and doesn't require opening your phone or handling any physical components.

Advantages of using eSIM for travel

1. Instant activation with no shipping to wait for

With a physical SIM, you have to order it ahead of time, wait for shipping (3-7 days), or buy one at the airport at inflated prices. With an eSIM, you buy online and activate it in minutes—even while you're sitting in the airport waiting area.

Real example: If you're flying from Mexico City to Madrid tomorrow, you can buy your eSIM tonight and activate it as soon as you land. No stress, no desperate hunting for stores in Barajas.

2. Multiple plans on one device

An eSIM can store up to 8 different profiles (though you'll normally use 2-3 active ones). This means you can have:

• Your Mexican physical SIM with Telcel for local calls
• A United States eSIM for when you cross the border
• A Europe eSIM for your trip to Spain
• A Japan eSIM for your vacation in Tokyo

All on the same phone, with no need to swap physical cards.

3. No risk of losing the card

Have you ever lost one of those tiny physical SIMs while swapping cards? It's more common than you think. With eSIM, there's nothing physical to lose. Your plan is linked to your device digitally and securely.

4. More competitive prices

eSIM providers have lower operating costs (they don't need to manufacture, store, or ship physical cards). That translates into lower prices for you.

Real price comparison (2026):

• Telcel roaming in Europe: $250 MXN/day
• Orange physical SIM in Spain: €30 EUR (~$600 MXN) for 15 days
• NAVEO Europe eSIM: $349 MXN for 15 days with 5GB

5. Greater security

eSIMs are harder to clone than physical SIMs. If you lose your phone, you can remotely deactivate the eSIM from your provider's app, preventing anyone from using your data plan.

6. Better for the environment

No plastic waste is generated and no physical shipping is required. According to a GSMA study, if all travelers used eSIMs instead of physical SIMs, more than 4,500 tons of plastic would be avoided every year.

7. Dual SIM without complications

Most modern phones support Dual SIM: one physical SIM + one active eSIM at the same time. This lets you:

• Receive calls on your Mexican number
• Use data from your international eSIM
• All at once, without changing any settings

Disadvantages and limitations of eSIMs

Device compatibility

Not all phones support eSIM. As of 2026, these are the most common compatible devices:

iPhone:

• iPhone XS, XS Max, XR and later (2018+)
• iPhone SE (2nd and 3rd generation)

Samsung:

• Galaxy S20, S21, S22, S23, S24 series
• Galaxy Note 20 series
• Galaxy Z Fold and Z Flip series

Google Pixel:

• Pixel 3 and later
• Pixel 3a and later

Others:

• Huawei P40, P50 series
• Motorola Razr (2019+)
• Sony Xperia 1 III and later

How to check: On your iPhone, go to Settings > Mobile Data > Add Data Plan. If you see this option, your device supports eSIM.

Transferring between devices

If you switch phones, you can't just remove the eSIM and insert it into your new device (like you would with a physical SIM). You need to:

1. Deactivate the eSIM on the old phone
2. Get a new QR code from the provider
3. Activate the eSIM on the new phone

This process is free but requires contacting tech support.

Dependence on initial connectivity

To download and activate an eSIM for the first time, you need an internet connection (WiFi or data from your physical SIM). If you arrive in a country without WiFi and without your local SIM active, you won't be able to install the eSIM until you have basic connectivity.

Solution: Activate your eSIM before you travel, while you still have WiFi at home.

What do you need to use an eSIM?

1. A compatible device

Check that your phone is on the list of compatible devices I mentioned above. If your phone is more than 5 years old, it probably doesn't support eSIM.

2. An unlocked phone

Your device must be unlocked to work with any carrier. If you bought your phone on a Telcel, AT&T, or Movistar plan, make sure it's unlocked before you travel.

How to check on iPhone: Settings > General > About > Carrier Lock. If it says "No SIM restrictions," it's unlocked.

3. A reliable eSIM provider

You need a provider that offers:

• Coverage at your destination
• Transparent prices with no hidden fees
• Tech support in your language
• A simple activation process

NAVEO offers eSIMs for more than 190 countries with support in Spanish and English, prices in Mexican pesos, and activation in under 5 minutes.

4. An internet connection for the initial activation

As I mentioned, you need WiFi or data to download the eSIM profile the first time. Once activated, it works independently.

Comparison: eSIM vs physical SIM vs roaming

Winner for travelers: The eSIM offers the best balance of price, convenience, and functionality for 90% of travelers.

When is an eSIM NOT right for you?

There are scenarios where a physical SIM or roaming may be better options:

Very short trips (1-2 days): If you'll only be in another country for 24-48 hours, the cost of activating an eSIM may not justify the benefit. Consider using free WiFi or limited roaming.

Older phones: If your device predates 2018, it probably doesn't support eSIM. In that case, a local physical SIM is your best option.

Remote areas without coverage: In very rural areas or countries with limited infrastructure, the networks associated with eSIM providers may not have coverage. Do your research before you travel.

Need for a local number: If you need a local phone number to make calls (not just data), a physical SIM from the country may be more practical. NAVEO eSIMs are primarily for data, though some include a local number.

Frequently asked questions about eSIM

Does the eSIM drain more battery than a physical SIM?

No. The eSIM chip uses the same power as a traditional physical SIM. The difference in battery life is imperceptible (less than 1%). What does drain battery is constantly searching for signal—if you're in an area with poor coverage, your phone will use more energy no matter what type of SIM you have.

Can I use my NAVEO eSIM on multiple devices?

No. Each eSIM is linked to a specific device through its IMEI (the phone's unique identifier). If you want to use data on your tablet or smartwatch, you need to buy a separate eSIM for each device.

What happens if my phone breaks or I lose it?

You can remotely deactivate your eSIM by contacting soporte@naveo.mx. Your plan will be temporarily suspended. Once you have a new compatible device, we can transfer your remaining plan (if applicable under the terms of the plan purchased).

Does the eSIM work if I travel to multiple countries?

It depends on the plan. NAVEO regional eSIMs (like "Europe" or "North America") work in all the countries in that region with no additional setup. Country-specific eSIMs only work in that country. If you're visiting France, Spain, and Italy, buy the "Europe" regional eSIM instead of three separate eSIMs.

Do I need to deactivate my Mexican SIM to use the eSIM?

Not necessarily. You can use Dual SIM: your active Mexican physical SIM for calls/SMS + your eSIM for data. Set your phone to use the eSIM as the default data network and keep the physical SIM to receive calls from Mexico.

How long does an eSIM take to activate?

2-5 minutes from the moment you scan the QR code. In rare cases it can take up to 15 minutes if there's high demand on the provider's servers. That's why we recommend activating your eSIM at least 1 hour before you need it.

Conclusion: Is the eSIM for you?

If you have a modern phone (2018+), you travel at least once a year, and you want to avoid the abusive costs of international roaming, the eSIM is definitely for you.

It's cheaper than roaming, more convenient than physical SIMs, and more secure than both. The technology is mature, prices are competitive, and activation is simpler than setting up email on your phone.

The only reason NOT to use an eSIM would be if your device doesn't support it or if you're traveling to extremely remote areas without coverage from the associated networks.

Ready to try an eSIM on your next trip? At NAVEO we offer eSIMs for more than 190 countries with instant activation, support in Spanish and English, and business invoicing. See available plans for your destination.

Sources consulted

• GSMA - eSIM Specification
• Apple - eSIM Support
• Samsung - eSIM Setup
• Google - Pixel eSIM Setup

About the author: This article was written by the NAVEO team, specialists in mobile connectivity for travelers. If you have questions about compatibility or activation, contact us at soporte@naveo.mx.