In short: if your eSIM doesn't activate, it's almost always due to one of these reasons: the QR code was already scanned, the WiFi disconnected during installation, the phone is locked by its carrier, or the APN needs to be configured. In this guide, we'll review all of them, ordered from most to least common, with step-by-step solutions so you can land with internet, no roaming, and no stress.
Installing an eSIM usually involves scanning a code and waiting a few seconds. But when something goes wrong and the eSIM doesn't activate on the day you're traveling, the feeling is awful. The good news: the vast majority of these failures have a simple technical explanation and a solution you can apply yourself in a few minutes. Let's diagnose the problem and solve it.
Quick Diagnosis: Identify Your Error
Before touching anything, pause for a second and identify exactly what's failing. A QR code that throws an error is not the same as an eSIM that installs but has no signal: these are different problems with different solutions. This table will take you directly to the section you need.
| What you see on screen | Most probable cause | Where to find the solution |
|---|---|---|
| "QR code no longer valid" or "QR expired" | Already scanned, even if installation failed | Errors with the QR code |
| "Cannot read QR code" | Image quality, brightness, or incorrect distance | Errors with the QR code |
| "Could not download profile" | Unstable WiFi or active VPN during installation | Network errors |
| "This device does not support eSIM" | Phone locked by its carrier or without actual eSIM support | Device issues |
| Installs but shows "No service" | eSIM not selected for data or roaming turned off | eSIM provides no data |
| Says "Active" but no browsing | Incorrectly configured APN or needs a restart | Advanced solutions |
With the symptom clear, jump directly to your section. If you've just landed and the problem is that your phone isn't connecting to any network after leaving the plane, we have a specific guide for that moment in what to do if your eSIM doesn't work upon landing.
Errors with the Activation QR Code
The QR code is the gateway to your eSIM, and also the number one source of scares. It's important to understand one key thing: an eSIM's QR code is for single use. It's not like a coupon you can scan multiple times; once you read it, the profile is "claimed" on the operator's server. If you want to understand in depth how this code works, we explain it in what an eSIM QR code is and how to use it.
"The QR code has already been used"
This message means that the QR code has already been scanned at some point, even if the installation was incomplete or you deleted it afterwards. You won't be able to reuse it from the camera. What to do:
- Go to Settings → Mobile Data / Network → Add eSIM or Add data plan.
- Look for the option "Enter details manually" or "Use activation code".
- If you have the SM-DP+ code (an alphanumeric string usually provided with the QR code in the email), enter it there instead of scanning.
- If neither the QR code nor the manual code works, write to support to have them regenerate your profile. This is a common procedure.
"Cannot read QR code"
Here the problem is not the profile, but that the camera cannot focus on the code. Try in this order:
- Turn the brightness to maximum on the screen displaying the QR code.
- Hold the camera about 20–30 cm from the code: neither too close nor too far.
- Avoid reflections or glare on the screen showing the QR code.
- If the QR code is printed, check that the paper is not wrinkled or folded across the middle of the code.
- Change rooms or lighting: sometimes that's enough.
A practical trick: always request the QR code on a second device (a laptop, a tablet, or a companion's phone) to scan it from yours. Scanning a QR code that is saved on the same phone that is trying to install it is precisely what you cannot do with the camera.
Network Errors During Installation
eSIM installation downloads a "profile" from the carrier's servers, and this requires a stable connection. This is a point that confuses many people, so it's worth clarifying.
"Could not download eSIM profile"
This is almost always a connection issue. Recommended steps:
- Connect to a stable WiFi network. Do not attempt to download the profile using data from another eSIM or SIM: the connection may restart during download and interrupt the process.
- Disconnect from WiFi and reconnect to refresh the connection.
- Try a different WiFi network (a coffee shop, a friend's hotspot, the hotel network).
- Disable your VPN if it's on: it interferes with profile download.
- Wait a few minutes and try again, in case there was a temporary server load spike.
If you prefer to do everything right from the start and avoid these hiccups, review our general guide on how to install an eSIM step-by-step before scanning anything. Installing the eSIM at home, with WiFi, and calmly before traveling is the best way to avoid depending on airport WiFi.
Device Issues
Sometimes the error isn't with the eSIM or the network, but with the phone itself. The typical message is "This device does not support eSIM" even on a model that on paper is compatible. This table summarizes the most common scenarios.
| Situation | What to do |
|---|---|
| iPhone or Android purchased with a contract and still locked | Request unlocking (liberation) from your carrier. In Spain, it's usually free once the contract is fulfilled. |
| iPhone 14 or 15 purchased in the USA | These models are eSIM-only with no slot, but are only sold in the USA. If it's also locked to an American carrier, it won't accept travel eSIMs until unlocked. |
| Android with eSIM deactivated by the carrier | Some carriers cap the function. Call and ask them to enable it. |
| Outdated operating system | Update to the latest version of iOS or Android before attempting to activate the eSIM. |
If you have doubts about whether your phone is truly compatible, don't take it for granted: check it in how to know if your phone is compatible with eSIM. Checking before buying the plan saves you most of the headaches.
eSIM Installs But No Data
This is the most baffling case: the eSIM appears installed, everything seems correct, and yet the phone says "No service" or doesn't browse. Before thinking the eSIM is broken, check these settings, which solve the vast majority of cases:
- Go to Settings → Mobile Data and confirm that the eSIM line is selected as the data line. If you have two lines, it's easy for the phone to continue using the primary one.
- Activate "Data Roaming" for the eSIM line. It sounds counterintuitive, but a travel eSIM connects to local networks that the phone interprets as roaming. Without this setting, it won't browse.
- Check that mobile data is turned on, not just WiFi.
- Verify in your account that the plan has started. If you purchased a plan with a future start date, it will not provide data until that day.
- Toggle airplane mode on and off for a few seconds to force the phone to search for a network again.
If you have done all this and still have no connection, the problem is usually with the APN. We'll cover this in the next section, and we have a dedicated guide in eSIM installed but no data.
Advanced Solutions: APN and Network Reset
Manually Configure APN
The APN (Access Point Name) is the address your mobile uses to connect to your eSIM's operator data network. Most eSIMs configure it automatically, but if yours ran out of data, setting it manually usually fixes it. Where to find it:
On iPhone: Settings → Mobile Data → tap your travel eSIM → Mobile Data Network → APN.
On Android: Settings → Network & internet / Connections → SIM → your eSIM → Access Point Names (APN) → Add.
The correct APN value appears in your plan confirmation email or on the product sheet. If you don't have it handy, consult how to configure your eSIM's APN and get it ready. An important detail: do not touch your main SIM's APN, only your travel eSIM's.
Reset Network Settings
When nothing works and the phone seems "stuck," resetting network settings often unblocks the situation.
On iPhone: Settings → General → Transfer or Reset iPhone → Reset → Reset Network Settings. Caution: This deletes saved WiFi passwords, so have them handy. After the reset, re-select the eSIM as the data line.
On Android: The path varies by brand, but it's usually in Settings → System → Reset options → Reset Wi-Fi, mobile & Bluetooth / Reset network settings. It does not delete your photos or apps, only connection settings.
What Almost No One Tells You
Beyond the classic error messages, there are details that are rarely explained and that prevent most problems. These are the ones that truly make a difference:
- Install before traveling, activate upon arrival. These are two different things. Many eSIMs allow you to install the profile at home with your WiFi (quiet download) and have the plan only start counting when you connect to a network in the destination country. This way, you arrive with everything ready and don't depend on airport WiFi.
- A used QR doesn't mean a lost plan. If you scanned the code and the installation failed, the plan is still yours. What is "consumed" is the QR, not the data. Request a new code and you're good to go.
- Roaming activated on the eSIM doesn't cost you money. This is the most common configuration error. Activating "data roaming" on the travel eSIM line is mandatory for it to work and does not generate charges from your Spanish operator, because the data goes through the eSIM plan, not your usual rate.
- Save the SM-DP+ code. It's the QR's Plan B. If you ever need to reinstall the eSIM and cannot scan the code with the camera, that alphanumeric string saves you. Take a screenshot of the complete activation email.
- Updating the operating system just before a trip causes problems. A partial update can leave network settings unstable. If you're going to update, do it a few days before, not the eve of your departure.
- Two eSIMs at once can conflict. If you have several profiles installed, check that the active one for data is correct. It's common to arrive in a country and have the phone still try to use the eSIM from the previous trip.
When to Contact Support
Most errors can be resolved with the steps above. However, there are situations where the fastest solution is to directly contact your provider's support:
- The QR code no longer works and you need a new one regenerated.
- The manual code returns "Invalid activation code" when entered.
- Profile download fails repeatedly, even with multiple different WiFi networks.
- Your phone is compatible and unlocked, but the error persists.
To get help quickly, have the following ready: the exact model of your phone, the operating system version, a screenshot of the error, and the email you used to purchase the plan. With this information, the team can diagnose the problem almost at a glance.
And if you're considering which plan to buy for your next destination with the peace of mind of having Spanish-speaking support, check out our most popular eSIMs, such as the eSIM for Europe or the eSIM for the United States. You'll land with internet from minute one, without searching for a store or struggling with roaming.
Frequently Asked Questions
Can I install the eSIM without WiFi?
You need a connection, usually WiFi, to download the profile. This is a requirement of the eSIM standard itself: the phone needs to communicate with the operator's server to download the profile. Once installed, the eSIM works without WiFi via the mobile network. That's why it's ideal to install it at home before leaving.
How many times can I scan the same QR code?
Only once. An eSIM QR code is single-use for security reasons. If you need to reinstall the eSIM (e.g., phone change, factory reset, accidental profile deletion), the provider must generate a new code for you. Your data plan is not lost: what expires is the code, not your balance.
Why did the eSIM install but I have no internet?
It's almost always one of these three settings: the eSIM is not selected as the data line, roaming for that line is off, or the APN is incorrect. Check them in Settings → Mobile Data. If it still doesn't work, resetting network settings usually resolves it.
Do I have to activate roaming for the eSIM to work?
Yes, and don't worry: activating "data roaming" on your travel eSIM line is normal and necessary. That eSIM connects to local networks that your phone interprets as roaming. Since the data goes through the eSIM plan and not your Spanish plan, it won't incur extra charges from your usual operator.
What if my phone says it doesn't support eSIM even though it should?
Most likely, it's locked to a carrier. Check if your phone is unlocked and, if not, request unlocking. It's also advisable to update the operating system and confirm that the model has actual eSIM support (some regional models, like certain US iPhones, change the SIM configuration). When in doubt, verify compatibility before purchasing the plan.
Can an eSIM be reinstalled on another phone?
It depends on the provider. Some allow reinstallation of the profile multiple times, while others generate a new code each time. On modern iPhones, there is also direct transfer between devices. If you are changing phones, ask your provider before deleting the active eSIM profile to avoid losing it.
Will I lose my data if the QR fails on the day of travel?
No. A QR that throws an error does not consume your plan. Your data balance is associated with your profile, not the activation code. Contact support, request a new code, and install it. That's why we always recommend installing and testing the eSIM one or two days before departure, with enough time to resolve any unforeseen issues calmly.
