There is never a good time for mobile data to stop working, especially when you have just landed in another country, trying to book an Uber, or need to message someone waiting for you. The good news is that travel eSIMs usually connect, and work as soon as you land. Any rare and minor problems are usually caused by one or two settings that can easily be fixed in a couple of minutes.
This eSIM troubleshooting guide walks through the checks we would normally recommend to a FlexySim customer, starting with the simplest fixes before moving into more detailed iPhone and Android troubleshooting. You do not need to be particularly technical. Work through the steps in order, change one setting at a time, and test your connection before moving to the next section.
Before you begin
Do not delete your eSIM while troubleshooting unless FlexySim Support specifically asks you to. Most eSIMs cannot simply be reinstalled using the same QR code after deletion.
Quick fix checklist
Before changing advanced settings, check the essential items below to ensure your FlexySim eSIM is correctly installed and activated. These checks will resolve a large percentage of travel eSIM connection issues.
- Your FlexySim eSIM appears in your phone's SIM or mobile network settings.
- The FlexySim eSIM line is switched on.
- FlexySim is selected as the SIM used for Mobile Data or Cellular Data.
- Data Roaming is enabled for the FlexySim eSIM.
- Mobile Data is switched on.
- Airplane Mode has been turned on for about 20 seconds and then turned off.
- Your phone has been restarted since the eSIM was activated.
- You are physically located in a country covered by the plan you purchased.
Expected result: You should see signal bars and a network indicator such as 4G, 5G or LTE. Open a webpage or map to confirm that data is working.
Before installing your eSIM
An eSIM needs a solid internet connection during installation because your phone must securely download the mobile plan. Install it while connected to reliable Wi-Fi, ideally before you leave home or while you still have access to dependable internet.
Installing an eSIM before travel does not mean the plan starts immediately. Activation timing depends on the specific plan. Many travel eSIMs begin when they first connect to a supported network at the destination, while some plans may begin at installation or another stated point. Always check the instructions supplied with your order.
- Confirm that your phone is unlocked and supports eSIM.
- Use stable Wi-Fi during installation.
- Keep the installation email or app details available.
- Do not scan the QR code using the same phone screen on which it is displayed; open it on another device or use manual installation details.
- Avoid renaming or deleting other SIMs until the new FlexySim eSIM is installed successfully.
1. Make sure the eSIM line is switched on
A travel eSIM can be installed correctly but remain disabled. Open your SIM settings, select the FlexySim line, and make sure Turn On This Line, Use SIM or Enable is active.
Why this works: An installed eSIM does not connect to a network while its line is disabled. Switching it on allows the phone to register with an available partner network.
2. Select FlexySim for mobile data
Dual-SIM phones can keep your home SIM active while using FlexySim for data. This is useful, but the phone must be told which SIM should provide the internet connection. Select FlexySim under Mobile Data, Cellular Data or Preferred SIM for data.
Avoid unexpected roaming charges: Where possible, disable mobile data switching or automatic data switching. This helps prevent your phone from falling back to your home SIM when the travel eSIM signal is temporarily weak.
3. Enable Data Roaming for FlexySim
Travel eSIMs often connect through local partner networks. Because your phone treats this as roaming, Data Roaming usually needs to be enabled on the FlexySim line. This setting does not create extra roaming charges from FlexySim beyond the plan you purchased.
Be careful to enable roaming on the FlexySim eSIM, not automatically on your home SIM. If your home provider charges international roaming fees, you may prefer to leave roaming disabled on that line.
4. Refresh the network connection
- Turn Airplane Mode on.
- Wait approximately 20 seconds.
- Turn Airplane Mode off.
- Allow the phone up to two minutes to reconnect.
- If necessary, restart the phone.
Why this works: Airplane Mode forces the phone to disconnect from all mobile networks and begin a fresh network registration when it is switched off.
iPhone troubleshooting
Apple changes the wording of mobile settings occasionally, but the overall process remains similar. Depending on your region and iOS version, begin in Settings and select Cellular, Mobile Data or Mobile Service.
Confirm the FlexySim line is active
- Open Settings.
- Tap Cellular, Mobile Data or Mobile Service.
- Under SIMs, select the FlexySim eSIM.
- Switch on Turn On This Line.
- Switch on Data Roaming.
Choose FlexySim for cellular data
- Return to the main Cellular or Mobile Data screen.
- Tap Cellular Data or Mobile Data.
- Select FlexySim.
- Turn off Allow Cellular Data Switching while troubleshooting.
Expected result: The FlexySim line should show a network name, signal bars and an indicator such as 4G, 5G or LTE.
Check network selection
Automatic network selection is normally best. If the phone displays No Service for several minutes, turn Automatic off and allow the list of available networks to load. Choose one of the supported networks shown in your FlexySim instructions. If one network does not connect, try another supported option.
Check the APN on iPhone
Most eSIM plans configure the Access Point Name automatically, however some require a specific APN. Go to the FlexySim line settings and look for Cellular Data Network or Mobile Data Network. Enter the APN exactly as supplied with your plan. Leave username and password blank unless your instructions provide values.
If the APN menu is not visible, the carrier profile may manage it automatically. In that case, do not reset unrelated network settings unless instructed by support.
APN accuracy matters: APNs are sensitive to spelling, spaces and punctuation. Enter the value exactly as provided and avoid adding quotation marks or extra spaces.
Android troubleshooting
Android menus vary by brand. Samsung commonly uses Settings > Connections > SIM manager or Mobile networks. Google Pixel often uses Settings > Network & internet > SIMs. Other manufacturers may use labels such as SIM cards & mobile networks, Mobile network or Dual SIM.
Enable the FlexySim eSIM
- Open Settings.
- Open Connections, Network & internet or Mobile network.
- Select SIM manager or SIMs.
- Switch on the FlexySim eSIM.
- Set FlexySim as the preferred SIM for Mobile Data.
Enable roaming on Android
- Open the FlexySim SIM or Mobile network settings.
- Find Data Roaming or Roaming.
- Switch it on for FlexySim.
- Confirm any warning message if it refers to the selected travel eSIM.
Check preferred network type
Use a setting such as 5G/4G/3G/2G automatic, 5G preferred or LTE/3G/2G automatic. Avoid selecting 5G only, because 5G coverage may not be available everywhere. An automatic setting allows the phone to use the strongest compatible network.
Check or create the APN on Android
- Open Settings and go to Mobile networks.
- Select FlexySim.
- Open Access Point Names.
- Choose an existing APN that matches the supplied details, or tap Add.
- Enter the APN exactly as supplied.
- Save the APN.
- Select the new APN using the radio button or check mark.
- Restart the phone.
Common Android mistake: Saving a new APN does not always select it. Return to the APN list and make sure the new entry is actively selected.
Understanding APN settings
APN stands for Access Point Name. It tells the phone how to connect to the mobile data service after it registers on a network. A phone may show signal bars even when the APN is missing or incorrect, which is why APN settings are especially important when calls or network registration appear normal but websites do not load.
Use only the APN provided for your specific FlexySim plan. Different destinations and network partners may use different settings. Do not copy an APN from an unrelated plan or online forum.
Manual network selection
Most phones should remain on automatic network selection. Manual selection becomes useful when the phone repeatedly chooses a network that provides weak service or does not complete registration.
Turn automatic selection off, wait for the network list to populate, and choose a supported partner network. Registration may take one or two minutes. If the first supported option fails, try another. Once connected, you can leave the phone on that network or return to automatic selection if the connection remains stable.
Be patient: The network list can take a minute or more to appear, especially immediately after landing or in areas with weak reception.
No Service, Searching or SOS Only
These messages mean the phone has not completed registration on a mobile network. Work through the following checks in order:
- Confirm you are inside the plan's covered destination.
- Make sure the FlexySim line is enabled.
- Enable Data Roaming on the FlexySim line.
- Set network selection to Automatic.
- Use Airplane Mode for 20 seconds.
- Restart the phone.
- Try manual network selection and choose a supported network.
- Move to an open area or near a window if you are inside an airport, basement or large building.
Airport arrivals: Mobile signal can be weak inside immigration halls, underground train platforms and baggage areas. Moving a short distance can sometimes make the phone register immediately.
The phone has signal, but data does not work
Signal bars show that the phone can see a network, but they do not always confirm that the data connection is configured correctly. Check the following:
- FlexySim is selected for Mobile Data.
- Data Roaming is enabled for FlexySim.
- The APN matches the plan instructions.
- Mobile Data is turned on.
- Any VPN is temporarily disabled while testing.
- The plan still has available data and has not expired.
- The phone is not using a restricted data-saving mode that blocks the app you are testing.
Simple test: Turn Wi-Fi off temporarily and open a basic webpage. This confirms whether the phone is genuinely using the mobile data connection.
Slow or unstable mobile data
Mobile speeds depend on local coverage, network congestion, signal strength, the phone model and the plan's high-speed data allowance. A 5G symbol does not guarantee that every location will be faster than 4G.
Try moving to another location, switching Airplane Mode on and off, manually selecting another supported network, or changing the preferred network type from 5G to LTE/4G automatic. Also check whether your plan includes a daily high-speed allowance followed by reduced speeds. If so, the full-speed allowance normally resets daily according to the plan rules.
QR code will not scan
- Display the QR code on a second device or computer.
- Increase the screen brightness.
- Make sure the entire QR code is visible and not cropped.
- Clean the phone camera lens.
- Use the phone's Add eSIM function rather than the ordinary camera app.
- Enter the manual installation details, or click the quick installation link.
Already used QR code: Many eSIM QR codes are designed for one installation only. If the eSIM already appears in your SIM settings, do not keep scanning the code. Continue with activation and connection troubleshooting instead.
Activation failed or eSIM cannot be added
Confirm that the phone supports using an eSIM, is not network locked, has a stable internet connection and has available eSIM capacity. Restart the device and try again over reliable Wi-Fi. If the error says the code is invalid, expired or already used, take a screenshot and contact FlexySim Support rather than deleting existing SIM profiles.
Accidentally deleted eSIM: Do not assume the original QR code will reinstall the eSIM. Contact FlexySim Support with your order number, phone model and a screenshot of the current SIM settings. The available solution depends on the plan and whether a replacement profile can be issued.
Hotspot or tethering is not working
Hotspot availability depends on the plan, network and device. First confirm that ordinary mobile data works on the phone. Then enable Personal Hotspot, Mobile Hotspot or Tethering and reconnect the second device.
On some phones, the hotspot APN is inherited automatically. On others, it may require the same APN as the mobile data connection. Some unlimited or fair-use plans may restrict tethering, so check the product description and supplied instructions.
Why calls and SMS may not work
All FlexySim travel eSIM plans are data-only. They provide internet access but do not include a standard local mobile number for voice calls or SMS. You can however easily make calls using internet-based services such as WhatsApp, FaceTime, Messenger, Teams or other calling apps.
You may keep your home SIM enabled to receive calls or SMS, including verification codes, but your home provider may charge for roaming services. Check its pricing before travel. To reduce the risk of mobile data roaming charges, keep your home SIM's data roaming disabled and select FlexySim as the mobile data line.
Avoiding accidental roaming on your home SIM:
- Set FlexySim as the Mobile Data SIM.
- Disable Allow Cellular Data Switching or automatic data switching.
- Turn off Data Roaming on your home SIM.
- Consider disabling the home SIM entirely when you do not need calls or SMS.
- Check the data usage screen to confirm which SIM is consuming data.
Things not to do while troubleshooting
- Do not delete the eSIM unless support instructs you to.
- Do not repeatedly reset every network setting before recording the original configuration.
- Do not enter APN details from another provider or destination.
- Do not enable roaming on the wrong SIM without checking possible charges.
- Do not assume the plan is faulty before confirming the active data SIM and roaming settings.
When to contact FlexySim Support
If the guide has not resolved the issue, send enough information for the support team to investigate without asking you to repeat every step. Include:
- Your FlexySim order number.
- The country and city where you are currently located.
- Your phone make and exact model.
- The operating system version.
- A screenshot showing the FlexySim eSIM line.
- A screenshot showing the selected Mobile Data SIM.
- A screenshot showing Data Roaming.
- A screenshot of the APN settings, if visible.
- The network name displayed by the phone.
- The exact error message or a brief description of what happens when you try to connect.
Privacy reminder: Do not publish or share the full eSIM QR code, activation code or other installation credentials in public posts or forums. Send sensitive details only through an official support channel.
Quick reference table
| Problem | Most likely check | Next step |
|---|---|---|
| eSIM will not install | Wi-Fi, device compatibility, phone lock | Use manual installation details or contact support |
| No Service or SOS | Line enabled, roaming, destination coverage | Refresh network and try manual selection |
| Signal but no internet | Active data SIM and APN | Select FlexySim for data and verify APN |
| Slow data | Signal, congestion, allowance | Try another supported network or LTE/4G |
| QR code already used | Check whether eSIM is already installed | Do not delete it; continue activation steps |
| Hotspot not working | Plan support and ordinary data connection | Check hotspot settings and APN |
| Cannot call or text | Plan may be data-only | Use an internet calling or messaging app |
Frequently asked questions
Should I install my travel eSIM before I leave home?
Yes, installing it over reliable Wi-Fi before departure is usually the easiest approach. Check the plan instructions so you understand when its validity begins.
Does Data Roaming need to be on?
Yes for the FlexySim travel eSIM, because it connects through partner networks. Keep roaming off on your usual home SIM if you want to avoid possible charges from your usual provider.
Why does my phone show signal but no internet?
The phone may be registered on a network while the wrong SIM is selected for data or the APN is missing. Check the active Mobile Data line, roaming and APN.
Can I keep my normal SIM switched on?
Yes. Many travellers keep it active for receiving calls or verification texts while using FlexySim for data. Check your home provider's roaming charges.
Can I use WhatsApp with a data-only eSIM?
Yes. WhatsApp and similar apps work over mobile data, and your existing account normally remains linked to your usual number.
Should I delete the eSIM and reinstall it?
No, not unless FlexySim Support specifically instructs you to. Many QR codes can be used only once.
Why is 5G not showing?
5G availability depends on the plan, network, device and location. LTE or 4G can still provide a fast and reliable connection.
Can I share the connection with a laptop?
Often yes, but hotspot availability depends on the plan and network. Confirm ordinary mobile data works first and check the plan conditions.
What should I send support?
Send the order number, location, phone model, screenshots of the SIM, roaming and APN settings, and the exact error message.
Final thoughts
Most travel eSIM issues come down to a small number of settings: the eSIM line needs to be enabled, FlexySim eSIM must be selected for mobile data, Data Roaming generally needs to be on, and the APN must match the plan instructions. Start with those basics before moving into manual network selection or more advanced troubleshooting.
Travelling can be stressful — getting online should not add unnecessary stress. Work through the guide calmly, change one setting at a time, and contact the FlexySim team at hello@flexysim.com with screenshots and device details if you still need a hand.
