When to Install an eSIM: Before Your Flight or After Landing?
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Short answer: install the eSIM at home, before you leave for the airport, and turn on data only when you land at your destination. Installing needs an internet connection, which you have at home but may not have on arrival, and with FlySim the plan's validity is counted from activation at the destination, not from purchase or installation.
Install at home, activate on landing
One of the most common questions before a trip abroad is when to install an eSIM. The answer is simple: install the eSIM at home, before you set off for the airport, and turn on data only when you land at your destination.
With FlySim, the plan starts counting only from actual activation at the destination, not from the moment you buy or install it. So you can install a few days in advance without losing a single day of your plan. (The exact validity rule for each plan is shown on its page.)
Why install your eSIM before the flight
- You need internet to install. Scanning the QR code requires a connection. At home you have stable Wi-Fi; when you land you might have no signal at all.
- You're connected the moment you land. You can send a "we've landed" message while still on the plane, book a taxi and navigate to your hotel without hunting for slow public Wi-Fi in the terminal.
- Peace of mind on a late arrival. Landing at night in a foreign city with no signal is exactly the situation you want to avoid.
- Time to fix problems. If something goes wrong during installation, at home you have time to contact support through the live chat on the website, rather than in the border control queue.
- No SIM kiosks or queues. Walk out of the terminal straight into your holiday.
When does the plan start counting?
This is the difference between installation and activation, and it's worth knowing:
| Step | When | Does the plan count? |
|---|---|---|
| Purchase | Any time | No |
| Installation (scanning the QR) | At home, before the flight | No |
| Activation | On landing, when the phone connects to the local network | Yes, validity counts from here |
Every FlySim plan has a validity period shown next to it (for example 30 days), counted from actual activation. In other words, installing early doesn't "eat" your days.
How to install an eSIM: step by step
At home, before the flight
- Check that your phone supports eSIM. Most phones from the last five years do. You can check in our compatibility checker.
- Buy a plan for your destination. Choose a destination and number of days, and you'll get a recommendation for the right amount of data.
- Scan the QR code. The code arrives by email right after payment. In your cellular settings choose "Add eSIM", scan and confirm. Full instructions are in our eSIM installation guide.
- Give the line a clear name, for example "FlySim", so it's easy to recognize when you land.
On landing
- Set the eSIM line as your mobile data line.
- Turn on roaming for the eSIM line only. Leave data roaming off on your home line to avoid charges. Here's how to turn on data roaming for the eSIM only.
- Wait a few minutes for the phone to connect to the local network, and that's it.
The eSIM is added alongside your existing SIM, so you keep your home number on the phone.
Common mistakes to avoid
- Waiting to install until you reach the airport at your destination. Without Wi-Fi you can't scan the code, and you're stuck.
- Deleting the eSIM after installing it. In most cases a QR code is single-use, and deleting it may mean contacting support.
- Forgetting to switch data to the eSIM line on landing. The phone will keep trying to use your home line for data.
- Leaving roaming on for your home line. That's the shortest route to surprise roaming charges.
- Not checking compatibility in advance. A phone that doesn't support eSIM can't install the plan.
Frequently asked questions
How long before my flight can I install an eSIM?
You can install a few days in advance. The plan only counts from activation at your destination, so installing early doesn't shorten its validity.
Can I install an eSIM after landing?
Yes, but you need a Wi-Fi connection to scan the QR code. That's why we recommend installing at home.
How long does installation take?
About 3 minutes on average, from scanning the code until the line appears on your phone.
Will I lose my home number?
No. The eSIM is added alongside your existing SIM, and your home number stays on the phone. More on keeping two numbers at once.
What if the eSIM doesn't work?
Contact support through the chat on the website, or go through our checklist for when an eSIM is not connecting after landing.
Ready for your trip? Choose your destination and install your eSIM today.