Travel guide

How to activate an eSIM step-by-step (iPhone and Android)

Marc González Sáez Marc González Sáez ·June 29, 2026 ·9 min. read
How to activate an eSIM step-by-step (iPhone and Android)

You already have your eSIM installed, but upon arriving at your destination, your phone isn't getting data: you're missing the last step, which is knowing how to activate an eSIM to start getting internet. Activating is not the same as installing, and confusing the two is the most common mistake that blocks travelers as soon as they land. 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 at first.

Install vs. Activate: The Key Difference

Before touching anything, it's important to understand two words that many people use as if they were the same, but they are not. To install an eSIM is when 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 not have internet simply because you haven't activated it yet.

The good news is that you've already done the difficult part: installing requires the QR code and is done only once. If you haven't done it yet, you can find complete 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, comfortably with your 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 provides no benefit and, depending on the plan, may start the validity countdown 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 stepping off the plane, without searching for stores or public WiFi networks. With PuraSim, the entire process is quick: the QR installs 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 in depth in the last section.

Activa la línea de datos de la eSIM al llegar a tu destino.
Activate your eSIM's data line when you arrive at your destination.

How to activate the data line on iPhone

On iOS, activating the eSIM means telling the iPhone to use that profile for mobile data and authorizing data roaming only on that line. It's a process that takes less than a minute. The switch that actually turns on your travel internet is the data roaming for that line, not for your main SIM. Follow these steps:

  1. Open Settings and go to Mobile Data (or "Cellular").
  2. Under Mobile Data, select your travel eSIM (it usually appears with the name you gave it, for example "Travel" or "PuraSim") as the line to be used for data.
  3. Tap on that same eSIM line and go to Data Roaming.
  4. 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.
  5. Make sure that your main line has roaming deactivated to avoid 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, see 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 menus change names 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:

  1. Open Settings and go to Connections or Network & internet.
  2. Go to SIMs or SIM cards & mobile networks and select your travel eSIM.
  3. Mark that eSIM as the line for Mobile Data (the preferred SIM for data).
  4. Within that eSIM's settings, activate Data Roaming only on that profile. Again, with PuraSim this does not generate roaming charges: you use local networks at local prices.
  5. Check that your main SIM keeps roaming off to avoid charges from your company.

On many Androids, 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 doubts about how the two lines coexist on your phone, it will help to read how eSIM and dual SIM work, because there we explain which line handles calls and which handles data.

When days and data start counting

This is one of the most frequently asked questions and deserves a clear answer, because it affects how long your plan lasts. For most travel eSIMs, including PuraSim, the plan validity counter does not start when the QR is installed, but when the eSIM first connects to a network in the destination country. That is, 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 browsing, with 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 early if your plan counts by days, so as not to "burn" days at the departure airport.
  • Estimate your consumption before choosing the plan: a guide on how much data you need for travel helps you avoid running short or paying too much.

If you run out of data at any time, it's fine: you can buy another plan and repeat the activation. And since PuraSim plans start from $0.85, extending is worthwhile.

What to do if the eSIM doesn't connect

Sometimes you activate everything correctly, and still, your phone doesn't get 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 your phone or adjusting the network selection. Try this in order:

  • Restart your phone: turn it off and on again once you've reached 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 on the main one), as we saw in the iPhone and Android sections.
  • Manual network selection: in Network Settings, deactivate automatic operator selection and choose a local network manually; if one fails, try another.
  • Check the APN: on some Androids, you need to enter the APN indicated by your provider for data to work. PuraSim provides this, and normally, it configures automatically.
  • Wait a few minutes: after landing, the network may take a little 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 your 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.

Keeping your number on your main SIM

One of the great appeals of a data eSIM is that you don't have to give up your usual number. The key lies in how you distribute 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 the 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 in both systems:

Step iPhone Android
Open network settings Settings > Mobile Data Settings > Connections (or Network & internet)
Choose data line "Mobile Data" > select eSIM "SIMs" > Preferred SIM for data: 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 at once, we recommend the guide on how dual SIM with eSIM works. And if you still don't have your plan, you can choose your eSIM for your next destination in a couple of minutes.

Frequently Asked Questions

Is activating an eSIM the same as installing it?

No. Installing is scanning the QR and saving the profile to your phone (this is done once, preferably from home). Activating is selecting that line for mobile data and enabling data roaming on it when you arrive at your destination. You can have the eSIM installed and still not have 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 upon arrival at your destination. This way, you'll be connected in a few minutes and, for plans that count by days, you won't start the clock early.

Do I have to activate data roaming? Isn't that roaming?

Yes, you must activate it, but only on the eSIM line. That switch only allows THAT line to use the network of the country you are visiting; since your PuraSim plan is for prepaid local data and works without roaming, it will not 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 by browsing, using maps, or watching videos.

I activated my eSIM and I don't have internet, what should I do?

Restart your phone once you're 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 handles data only. 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 arriving 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's eSIM support if you need details for your model.

Marc González Sáez
Written by Marc González Sáez Founder of PuraSim and a specialist in eSIM and connectivity for travelers. He has been helping people travel connected worldwide for years without overpaying for roaming, and personally tests eSIMs in each destination before recommending them.
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