How eSIM Works

A plain-English guide to what an eSIM is, why it is better than a plastic SIM, and how to use one.

What is an eSIM?

An eSIM (embedded SIM) is a digital version of the plastic SIM card that has been inside phones for decades. Instead of a removable chip you slide into a tray, an eSIM is a tiny component soldered permanently into your phone's circuit board.

The key difference: a physical SIM card stores your carrier information on the card itself. An eSIM stores that information in a secure, reprogrammable chip. You can load different carrier profiles onto the same eSIM chip, meaning you can switch networks without ever touching a physical card.

eSIM vs physical SIM: what is the difference?

	eSIM	Physical SIM
Setup	Scan a QR code in 2 minutes	Buy in a shop, insert manually
Switching carrier	Instantly in Settings	Swap physical card
Multiple plans	Store up to 8+ profiles	One card per slot
Lost or stolen	Cannot be physically taken	Card can be stolen
Travel use	Activate before you fly	Find a local SIM on arrival
Environmental	No plastic waste	Plastic card per network

How does an eSIM work technically?

When you buy an eSIM plan, the provider generates a carrier profile — a secure file containing the network credentials for your chosen destination. This profile is encoded into a QR code and sent to you by email.

When you scan the QR code, your phone downloads and installs the profile onto the eSIM chip. Your phone can then authenticate itself to the carrier's network, just as it would with a physical SIM. The profile is stored securely and encrypted — only your device and the carrier's servers can read it.

How to install an eSIM: step by step

Buy your eSIM plan

Choose your destination and data allowance on the LimitFlex store. Complete your purchase — the whole process takes about two minutes.

Receive your QR code

Your eSIM QR code arrives by email, usually within seconds of purchase. No waiting for a card to be posted.

Open phone Settings

On iPhone: Settings → Cellular → Add eSIM. On Android: Settings → Connections → SIM Manager → Add eSIM.

Scan the QR code

Hold your phone's camera up to the QR code on screen or in the email. Your phone will detect it automatically and prompt you to confirm installation.

Label the eSIM

Give it a name like 'Travel Data' so you can find it easily in Settings. Set your home SIM as your primary number for calls.

Activate on arrival

Keep the eSIM toggled off until you land. Switch it on when you arrive — your phone will connect to the local network automatically.

Which devices support eSIM?

eSIM is now standard on almost all flagship smartphones. Compatible devices include:

+iPhone: iPhone XS / XR (2018) and all newer models. iPhone 14 USA models are eSIM-only.
+Samsung Galaxy: S20 series (2020) and all newer flagship and mid-range models.
+Google Pixel: Pixel 3 (2018) and all newer models.
+Other Android: Most 2022+ flagships from OnePlus, Sony, Motorola, and Xiaomi.
+Tablets and watches: iPad Air / Pro (2018+), Apple Watch Series 4+ (cellular models).

See the full compatible devices list →

Ready to try an eSIM?

Browse plans for 190+ destinations. Buy before you fly, connect on landing.

Browse eSIM Plans

Frequently asked questions

What does eSIM stand for?

eSIM stands for embedded SIM. Unlike a traditional plastic SIM card, it is a small chip already soldered inside your phone. You activate it by downloading a carrier profile, usually by scanning a QR code.

Is eSIM secure?

Yes. eSIM profiles are encrypted and tied to your specific device. They cannot be physically stolen like a plastic SIM card can. The GSMA (the global mobile standards body) oversees strict security requirements for all eSIM profiles.

Can I have more than one eSIM?

Most modern phones can store multiple eSIM profiles but only activate one at a time (or two if the device supports dual eSIM). This is useful for having your home SIM and a travel SIM on the same phone without carrying two physical cards.

Does eSIM work everywhere?

eSIM technology is supported by networks in over 200 countries. The specific coverage depends on which networks your eSIM provider has partnered with. LimitFlex eSIMs cover 190+ countries using local network partnerships.

What happens to my eSIM if I change phones?

eSIM profiles are tied to a specific device. If you get a new phone, you will need to transfer or reinstall your eSIM profiles. Most providers allow you to re-download a profile to a new device, though policies vary.

Want to know how to install yours? iPhone guide · Android guide