Guidance & practice

How does a eSIM work?

From booking to surfing - explained step by step.

A eSIM sounds technical, but it's surprisingly simple. Here you can find out exactly how to buy, install and activate a eSIM - including tips, typical mistakes and what you really need.

Best eSIM providers Browse country guides

How a eSIM works in practice

A eSIM works like a normal SIM card - only digital. Instead of a plastic card, a mobile phone profile is electronically loaded onto the eSIM chip in your smartphone. This chip is already installed ex works.

The process is simple: you choose a provider, buy a tariff and receive QR-Code or app access. After scanning, the profile is loaded onto your device. In the settings, activate eSIM as the data tariff - done.

The special feature: You can save several eSIM profiles on your device and switch between them. Ideal if you regularly travel to different countries.

QR-Code scan

After the purchase you will receive a QR-Code. Your smartphone reads it and loads the mobile profile automatically.

App installation

Alternatively, providers such as Airalo and Holafly offer their own apps that guide you step by step through the setup process.

Connected immediately

After activation, your device automatically connects to the local mobile network - without any waiting time.

eSIM in 5 steps

Select tariff

Compare providers (Airalo, Holafly, Nomad) and choose a data plan for your destination - via app or website.

eSIM buy

Pay the tariff online. You will immediately receive a QR-Code by e-mail or directly in the app.

QR-Code scan

Open the camera or settings of your smartphone and scan the QR-Code. The eSIM profile is loaded.

eSIM activate

Go to Settings → Mobile and select the new eSIM as the data tariff. Activate data roaming.

Go online

After landing in your destination country, your device connects automatically. You are online immediately.

Why eSIM?

Set up in 5 minutes

The complete installation takes less than 5 minutes - from purchase to active connection.

No hardware required

No SIM card tool, no card change. Everything happens digitally on your existing smartphone.

Prepare before the trip

You can install the eSIM days before departure and only activate it at your destination.

No hidden costs

You pay the selected tariff once. No automatic renewal, no surprises.

Best eSIM providers

Our top recommendations compared.

Best Overall

Airalo

Worldwide eSIM with over 200 countries, fast activation and flexible data packages.

200+ countries covered
Top-rated app
Fast activation

4.8 / 5 ab 4 €

View details

Best Value

Nomad

Inexpensive eSIM with stable performance for budget travelers.

Low rates from € 5
100+ countries
Simple setup

4.5 / 5 ab 5 €

View details

Best Unlimited

Holafly

eSIM with unlimited data volume for stress-free travel.

Real unlimited data
Ideal for longer trips
No data limit

4.6 / 5 ab 19 €

View details

Common issues & solutions

What to do when your eSIM doesn't work.

Forget data roaming

The most common error: Data roaming is not activated. Without this setting, the eSIM will not work abroad.

Wrong line selected

Make sure that the eSIM is selected as the data plan - not your main SIM with expensive roaming.

No WLAN during installation

The initial installation requires an Internet connection. Install the eSIM at home in the WLAN.

Activated too late

Some tariffs start immediately after installation. Check beforehand whether the tariff only starts at your destination.

Network selection to manual

Set the network selection to 'Automatic'. Manual selection can prevent the eSIM from connecting.

Old eSIM profile blocked

Delete old, no longer used eSIM profiles to avoid space and conflicts.

Which traveler are you?

For vacationers

You are traveling for 1-2 weeks and need internet for navigation, WhatsApp and social media. The setup takes 5 minutes.

Tip: Install the eSIM the evening before the flight. After landing, only activate data roaming.

For short trip travelers

Even for a weekend, a eSIM is worthwhile. Small tariffs with 1-3 GB are available from €3.

Tip: Use the app-based installation for the quickest start.

For business travelers

Reliable Internet from the moment you land - without having to search for SIM cards at the airport.

Tip: Install Holafly Unlimited and set it as the default data plan.

For technology beginners

Don't worry: the apps from Airalo and Holafly will guide you step by step. Easier than changing a SIM card.

Tip: Start with Airalo - the app has the best step-by-step instructions.

Frequently asked questions

How do I install a eSIM on the iPhone?

Go to Settings → Mobile → Add eSIM → Scan QR-Code. Alternatively, use the provider's app (e.g. Airalo), which will automatically guide you through the process.

How do I install a eSIM on Android?

Go to Settings → Network & Internet → SIM cards → Add eSIM → Scan QR-Code. The exact menu items vary slightly depending on the manufacturer.

Do I need WLAN for the installation?

Yes, the initial installation requires an Internet connection. After that, the eSIM works independently via mobile radio.

When should I install the eSIM?

The best time to do this is 1-2 days before the trip at home in the WLAN. Activation then only takes place at your destination by switching on data roaming.

Can I install eSIM without QR-Code?

Yes, most providers offer app-based installation. Airalo and Holafly have their own apps with automatic setup.

What do I do if the eSIM does not work?

Check: 1. data roaming activated? 2. correct line selected as data tariff? 3. network selection set to automatic? 4. restart the device. This solves 90% of all problems.

Do I have to remove my normal SIM card?

No. Your normal SIM remains in the device. The eSIM is used as an additional data plan (dual SIM).

How do I switch between eSIM and normal SIM?

In the mobile settings, you can choose which SIM is used for data and which is used for telephony. Switching takes seconds.