What Is an eSIM? How Travel eSIMs Work

Q: Does an eSIM give you a phone number?

Most travel eSIMs (including SimYak's) are data-only — they provide internet access but not a callable number. For voice + SMS, keep your primary SIM active alongside the eSIM, or use apps like WhatsApp / FaceTime over the eSIM data connection.

What Is An eSIM Card?

eSIM stands for embedded SIM and functions as a digital version of a SIM card embedded in your device. Unlike physical SIM cards, eSIMs offer greater flexibility allowing you to switch between carriers seamlessly without swapping out SIM cards.

Whether you're hopping between countries or need a backup data plan, eSIM makes staying connected effortless. As long as your phone is compatible, you're good to go.

eSIM Explained

At a technical level, an eSIM is a programmable chip built into your device's hardware. It complies with the eUICC (embedded Universal Integrated Circuit Card) standard, which allows your device to securely download and manage mobile network profiles over the air — without ever needing to insert or remove a physical SIM.

This remote provisioning capability is what makes eSIM technology so powerful. Users can switch carriers, activate a new plan, or manage multiple profiles on a single device — all digitally. It's not just about convenience; it's also about scalability and security, especially for users managing international travel, work and personal lines, or backup data plan options.

For businesses and consumers alike, eSIM enables more flexible, efficient, and future-ready connectivity — no more physical logistics, just seamless digital management.

Cost-effective data plans

Skip pricey roaming charges with affordable local plans that fit any trip length.

Convenience & seamless activation

Install once, scan a QR code, and you're online — no SIM swap, no airport queue.

Flexibility across multiple countries

Switch carriers or regions digitally — perfect for multi-stop trips and digital nomads.

Dual SIM functionality

Keep your home number active for calls and texts while the eSIM handles data abroad.

Enhanced security

Embedded SIMs can't be stolen or swapped — your number stays yours, everywhere.

Environmentally friendly

No plastic SIM cards, no packaging, no shipping — sustainable connectivity by design.

eSIM

SIM

Phone numbers

Supports multiple phone numbers on a single device.

Typically supports only one number per SIM card.

Network operators

Not tied to a single carrier; allows switching between providers digitally.

Locked to a specific carrier unless the device is unlocked.

Removal

Embedded in the device and cannot be physically removed.

Can be removed and swapped between devices.

Activation

Activated digitally via software — no need for physical handling.

Requires manual insertion and activation through a carrier.

Carrier switching

Allows remote network switching without changing SIM cards.

Requires swapping out the SIM card to switch carriers.

Multiple profiles

Can store multiple carrier profiles on one device — useful for travellers and business users.

Supports only one profile per SIM; dual SIM slots required for multiple numbers.

Device compatibility

Available on newer flagship devices (iPhones, Samsung, Google Pixel, etc.).

Compatible with most mobile phones, including older models.

Myth 1 - eSIMs are Expensive

Contrary to popular belief, eSIMs are designed to be cost-effective, not expensive. At SimYak, our goal is to get you connected quickly and affordably, no matter where you are in the world.

Since eSIMs are distributed digitally, they eliminate production and logistics costs associated with physical SIM cards. This means lower prices for consumers — the primary costs come from backend telecom infrastructure rather than distribution.

And it's not just us — most eSIM providers offer competitive data plans in many countries. For instance, in Mexico, eSIM plans can be as affordable as local SIM card prices — without the hassle of physically swapping cards.

Myth 2 - eSIMs only work on the latest phones

While eSIM technology launched with newer flagships, it's now supported on a wide range of devices going back several years — including iPhone XS / XR (2018) and most Android flagships from 2019 onwards.

Before you travel, check your device's eSIM compatibility list on our Compatible Devices page. You may be surprised to find your current phone is already eSIM-ready.

What does an eSIM card do?

An eSIM is a digital, embedded SIM that lets you activate a mobile data plan instantly — no physical card needed. It does the same job as a traditional SIM, but it's programmed onto a chip that's already inside your device, so you can switch carriers or plans with a single QR-code scan.

How can I get an eSIM?

Purchase an eSIM plan on simyak.com, receive a QR code by email, and scan it from your phone's mobile-data settings. Most installs take under 2 minutes.

Is eSIM better than a SIM card?

For travel and dual-line setups, yes — eSIMs are faster to install, can't be physically lost or stolen, support multiple carrier profiles on one device, and let you switch networks without swapping cards. Traditional SIMs still win if you frequently move a single number between devices.

Why would I want an eSIM?

The main reasons are: lower roaming costs when travelling abroad, the ability to run two numbers on one phone, instant activation from anywhere, and zero plastic-waste from physical SIMs.

Why are eSIMs not popular?

Adoption is actually growing fast — eSIM is supported on every flagship phone released since 2018 and is becoming the default in newer markets. The perceived slow uptake is mainly because some users aren't aware their phone already supports it, and a few carriers still default to physical SIM for new activations.

Is an eSIM safer than a SIM?

Yes — because the eSIM is embedded in your device's hardware, it can't be physically removed or stolen the way a plastic SIM can. This makes SIM-swap fraud significantly harder against an eSIM-only line.

Does an eSIM give you a phone number?

Most travel eSIMs (including SimYak's) are data-only — they provide internet access but not a callable number. For voice + SMS, keep your primary SIM active alongside the eSIM, or use apps like WhatsApp / FaceTime over the eSIM data connection.

Does an eSIM work without an internet connection?

An eSIM provides the internet connection itself — once it's installed and activated, your phone uses it the same way it uses a physical SIM. To download the profile during install you'll need Wi-Fi or another working connection, but day-to-day it works wherever there's cell coverage.

Does an eSIM drain your phone battery?

An eSIM uses roughly the same amount of power as a physical SIM. Running dual-SIM (two profiles active at once) can use slightly more battery because the phone maintains two radio connections — but it's a small difference.

Can you convert an eSIM back to a physical SIM?

Not directly — eSIM profiles can't be transferred to a plastic SIM. However, you can typically port your phone number from an eSIM to a physical SIM (or vice versa) through your carrier, just as you would between any two SIMs.