You've already installed your eSIM, but when you arrive at your destination, your phone doesn't connect to data: you're missing the last step, which is knowing how to activate an eSIM so it starts giving you internet. Activating is not the same as installing, and confusing the two is the mistake that most often blocks travelers right after landing. In this guide, we explain, without technical jargon, how to turn on your eSIM's data line on iPhone and Android, when to do it, when your days and data start counting, and what to try if something doesn't connect the first time.
Install vs. Activate: The Key Difference
Before touching anything, it's good to be clear about two words that many people use as if they were the same, but they are not. To install an eSIM is the moment you scan the QR code and the profile is saved on your phone, like a second digital card that already lives inside the device. To activate is the subsequent step: telling your phone to use that line for mobile data and allowing it to connect to the network of the country you are visiting. You can have a perfectly installed eSIM and still have no internet simply because you haven't activated it yet.
The good news is that you've already completed the difficult step: installation requires the QR and is done only once. If you haven't done it yet, you'll find full details in our guide on how to install an eSIM, and the specific version for iPhone in eSIM installation and activation on iPhone. We won't repeat that step here: we assume your profile is already on your phone and we'll focus on what almost no one explains well, which is turning it on to connect. If you still have doubts about the technology itself, first review what an eSIM is and then come back here.
When to activate your eSIM (upon arrival at destination)
Timing matters, a lot. The general recommendation is to install the profile before leaving home, with your comfortable WiFi, but activate the data line only when you are already at your destination. Why separate the two moments? Because installation requires an internet connection to download the profile, and you can do that comfortably from home; however, activating the data network prematurely doesn't add anything and, depending on the plan, can start the validity counter before you actually need internet.
In practice, the ideal plan is this: you download and install the QR at home, board the plane with the eSIM already inside but not activated, and upon landing, you turn on the data line following the steps in the following sections. This way, you'll be connected within minutes of landing at the airport, without looking for stores or public WiFi networks. With PuraSim, the entire process is fast: the QR is installed in 1 minute and activation is a matter of a couple of taps. Remember also to deactivate roaming on your main line to avoid paying roaming charges with your usual operator; we cover that point thoroughly in the last section.
How to activate the data line on iPhone
On iOS, activating the eSIM means telling your iPhone to use that profile for mobile data and authorizing data roaming only on that line. This process takes less than a minute. The switch that truly turns on your travel internet is the data roaming for that specific line, not your main SIM. Follow these steps:
- Open Settings and go to Mobile Data (or "Cellular").
- Under Mobile Data, select your travel eSIM (it usually appears with the name you gave it, for example "Travel" or "PuraSim") as the line used for data.
- Tap on that same eSIM line and go to Data Roaming.
- Activate Data Roaming only on the eSIM line. This is necessary for it to connect to the local network of the country and does not imply paying roaming charges, because your PuraSim eSIM works without roaming at local prices.
- Make sure your main line has roaming deactivated to avoid generating charges from your operator.
Activating "data roaming" on the eSIM line sounds contradictory, but it's normal and safe: that setting only allows THAT line to use the network of the visited country. Since your plan is for prepaid local data, there's no surprise bill.
If your iPhone allows it, it's also advisable to deactivate data roaming on the main line from its options, leaving all traffic to the eSIM. For previous installation details, refer to the guide on eSIM on iPhone: installation and activation.
How to activate the data line on Android
On Android, the concept is identical, although the menu names change depending on the manufacturer (Samsung, Google Pixel, Xiaomi, etc.). The idea is the same: choose that line as the preferred mobile data and activate data roaming only on that profile. These are the general steps:
- Open Settings and go to Connections or Network & internet.
- Go to SIMs or SIM cards & mobile networks and select your travel eSIM.
- Mark that eSIM as the line for Mobile data (the preferred SIM for data).
- Within the eSIM settings, activate Data Roaming only on that profile. Again, with PuraSim, this does not generate roaming charges: you use local networks at local prices.
- Check that your main SIM keeps roaming off to avoid charges from your carrier.
On many Android phones, you'll see a quick selector in the notification bar to change which SIM uses data: use it to confirm that the eSIM is selected. If you have questions about how both lines coexist on your phone, reading about how eSIM and dual SIM work will help, as we explain which line handles calls and which handles data.
When do the days and data start counting?
This is one of the most frequently asked questions and deserves a clear answer, as it affects how long your plan lasts. For most travel eSIMs, including PuraSim, the plan's validity counter does not start when you install the QR, but when the eSIM first connects to a network in the destination country. In other words, the clock starts ticking with the first real connection, not before. That's why you can safely install the eSIM days before your trip without "wasting" time.
Regarding data, consumption is very intuitive: every megabyte you use for browsing, maps, video, or messaging is deducted from your data allowance as the local network provides you with internet. There is no intermediate roaming or surcharges for using one network or another within the destination. Two practical tips:
- Do not activate the data line prematurely if your plan is counted by days, to avoid "burning" days at the departure airport.
- Estimate your consumption before choosing a plan: a guide on how much data you need for travel will help you avoid running out or overpaying.
If you run out of data at any time, it's no problem: you can buy another plan and repeat the activation. And since PuraSim plans start from $0.85, extending your plan is cost-effective.
What to do if the eSIM doesn't connect
Sometimes you activate everything correctly, and yet your phone doesn't connect to the internet in the first few minutes. This is normal and almost always resolved in a couple of steps. 90% of cases are fixed by restarting the phone or adjusting the network selection. Try this in order:
- Restart your phone: turn it off and on again at your destination. This is the most effective trick for the eSIM to register the local network.
- Confirm data roaming: check that it is activated on the eSIM line (not the main one), as we saw in the iPhone and Android sections.
- Manual network selection: in Network Settings, disable automatic operator selection and manually choose a local network; if one fails, try another.
- Check the APN: on some Android devices, you need to enter the APN indicated by your provider for data to work. PuraSim provides this, and it usually configures automatically.
- Wait a few minutes: after landing, the network may take a while to fully activate. Turn airplane mode on and off to force a search.
If after all this you still don't have a connection, don't get stuck: we have a dedicated guide on what to do when the eSIM doesn't connect abroad with more solutions, and our 24/7 Spanish-speaking support is available to help you at any time from any of the 218 destinations.
Keep your number on the main SIM
One of the great attractions of a data eSIM is that you don't have to give up your usual number. The key is how you distribute the functions between your two lines: the travel eSIM handles data, and your main SIM stays in the phone for your number, calls, and SMS. This way, you can receive the typical verification code via SMS from your bank or WhatsApp without changing anything in your digital life.
The recommended setting when traveling is clear: leave your main SIM active for voice and SMS, but with data roaming deactivated on that line, and put all data in charge of the eSIM. This way, your number remains operational for receiving important calls and messages, but you don't spend a single cent on data roaming with your operator. The following table summarizes the steps for both systems:
| Step | iPhone | Android |
|---|---|---|
| Open network settings | Settings > Mobile Data | Settings > Connections (or Network & internet) |
| Choose data line | "Mobile Data" > select eSIM | "SIM" > Preferred SIM for data: the eSIM |
| Activate roaming on eSIM | Tap eSIM > Data Roaming: ON | eSIM settings > Data Roaming: ON |
| Main SIM roaming | Tap main SIM > Roaming: OFF | Main SIM settings > Roaming: OFF |
| Calls and SMS | Default line: Main SIM | Preferred SIM for calls: Main SIM |
To delve deeper into how to manage both lines simultaneously, we recommend the guide on how dual SIM works with eSIM. And if you don't have your plan yet, you can choose your eSIM for your next destination in a couple of minutes.
Frequently asked questions
Is activating the eSIM the same as installing it?
No. Installing means scanning the QR code and saving the profile to your phone (this is done only once, preferably from home). Activating means selecting that line for mobile data and enabling data roaming on it upon arrival at your destination. You can have the eSIM installed and still have no internet until you activate it.
When should I activate my eSIM's data line?
Ideally, install the QR at home with Wi-Fi and activate the data line only when you arrive at your destination. This way, you get connected in a few minutes, and for plans that count by days, you don't start the counter prematurely.
Do I need to activate data roaming? Isn't that roaming?
Yes, you should activate it, but only on the eSIM line. That switch only allows THAT line to use the network of the country you're visiting; since your PuraSim plan is for prepaid local data and works without roaming, it doesn't generate a surprise bill. Roaming on your main SIM should remain deactivated.
When do my plan's days and data start counting?
For most travel eSIMs, including PuraSim, validity begins with the first actual connection to a network in the destination country, not when the QR is installed. Data is deducted as you consume it while browsing, using maps, or watching videos.
I activated the eSIM and I don't have internet, what should I do?
Restart your phone once you've arrived at your destination, confirm that data roaming is active on the eSIM line, try manual network selection, and check the APN if your Android requires it. If it still doesn't work, consult our guide on eSIM not connecting or contact our 24/7 Spanish-speaking support.
Do I lose my phone number when using an eSIM?
No. Your main SIM remains in your phone for your number, calls, and SMS, and the eSIM only handles data. This way, you receive codes via SMS and important calls without paying data roaming with your operator.
Conclusion
Activating an eSIM is much simpler than it seems once you understand the difference from installing: you scan the QR at home, and upon arrival at your destination, you just need to select the eSIM for mobile data and activate data roaming only on that line, leaving your main SIM for calls and SMS. If it doesn't connect at first, restart, check the APN, or manually select the network. Remember that validity begins with the first real connection and that with PuraSim you have 218 destinations, plans from $0.85, QR in 1 minute, no roaming, with hotspot, and 24/7 Spanish-speaking support. Choose your eSIM and travel connected or consult Apple support for eSIM if you need details for your model.
