What is an eSIM and how does it work?
mySIM24 Team · Published 7/3/2026 · Updated 7/15/2026 · 3 min read
What is an eSIM?
An eSIM ("embedded SIM") is a digital SIM card built permanently into your smartphone. Instead of inserting a plastic card, you load a mobile profile onto your device via a QR code – in under two minutes.
How does an eSIM work?
- You buy a data plan and instantly receive a QR code.
- You scan the QR code in your device settings (or install it on an iPhone with a single tap).
- As soon as you arrive at your destination, the eSIM connects to the local network automatically.
Who is an eSIM worth it for?
- Travellers who want to avoid roaming charges
- Frequent flyers running several profiles at once
- Anyone who wants to keep their home number and still get online cheaply abroad
With mySIM24 you get eSIM data plans for over 130 countries – no contract, no hidden costs. Check the device compatibility.
eSIM, profile and plan: the difference
The eSIM is the embedded chip. A digital SIM profile containing the operator credentials is downloaded onto it. The plan defines data, validity, countries and price. A compatible phone can store several profiles, although the number that can remain active varies by model.
Why use an eSIM when travelling?
- Fully online purchase and delivery
- Installation before departure
- Keep the home SIM and familiar number in the phone
- Switch easily between country and regional plans
- No tray tool or loose card
Are there drawbacks?
You need a compatible, unlocked device and normally Wi-Fi for setup. A QR code is often single-use. Travel eSIMs are also commonly data-only and include no conventional phone number. Calls then use messaging or internet calling services.
Is an eSIM secure?
The profile is downloaded securely to the device. Treat QR and activation details as credentials and never post them publicly. Use a device lock and current operating-system updates.
Next steps
Check the phone on our compatibility page, then choose a destination package in the plan finder. Our iPhone and Android installation guide covers setup in detail.
What happens during activation?
When the QR code is scanned, the device connects to a secure provisioning server and downloads the assigned profile. The eSIM then authenticates on a mobile network in the same way as a traditional SIM. The profile cannot simply be copied to another phone, so do not delete an activated profile without checking the rules.
Digital SIM FAQ
Does an eSIM always need internet? Only the initial download needs an existing connection, normally Wi-Fi. Afterwards it uses the purchased mobile network.
Can I keep my WhatsApp number? Yes. WhatsApp remains registered to the familiar number while the travel eSIM supplies data.
Is an eSIM prepaid? The technology itself is neither prepaid nor contract. Travel offers are commonly prepaid data packages. See our contract-free prepaid eSIM guide.
If you already received a code, follow the eSIM QR code activation guide.