If your eSIM is not working in Taiwan, the problem is usually related to mobile data selection, Data Roaming, the APN or network registration. In many cases, the eSIM is installed correctly but has not been configured as the phone’s active internet line.
Start by confirming that the travel eSIM is turned on, selected for mobile data and allowed to use Data Roaming. You should also disable automatic data switching so the phone does not return to your home SIM.
Do not delete the eSIM while troubleshooting. Many travel eSIM QR codes are valid for one installation only, and removing the profile may prevent you from using it again.
Quick answer: Select the Taiwan eSIM for mobile data, enable Data Roaming, disable automatic switching, confirm the APN is data.esim, turn Airplane Mode on for 30 seconds and restart the phone if necessary.
Top Taiwan eSIMs
First Check: Is the Taiwan eSIM Installed?
Before changing network settings, confirm that the eSIM profile appears in your phone.
Look for a line labelled:
- Taiwan.
- NoveSIM.
- Travel.
- Secondary.
- Business or Personal, if the default label was not changed.
On iPhone, open:
Settings → Cellular or Mobile Service
On Samsung, open:
Settings → Connections → SIM Manager
On Google Pixel, open:
Settings → Network & Internet → SIMs
If the profile appears in the SIM settings, it has already been installed. Do not scan the QR code again and do not remove the profile.
Taiwan eSIM Troubleshooting Checklist
| Check | Correct Setting |
|---|---|
| Travel eSIM profile | Installed and enabled |
| Mobile data line | Taiwan eSIM selected |
| Data Roaming on travel eSIM | Enabled |
| Data Roaming on home SIM | Disabled |
| Automatic data switching | Disabled |
| Network selection | Automatic |
| APN | data.esim |
| WiFi during testing | Turned off |
1. Confirm That You Are in Taiwan
A Taiwan eSIM may not connect before you arrive in an included destination. Installation can usually be completed before departure, but network activation often begins only after the profile detects a supported network.
If you are still outside Taiwan:
- Keep the profile installed.
- Do not repeatedly scan the QR code.
- Wait until arrival before testing mobile data.
- Review the activation conditions of your exact plan.
After landing, allow several minutes for the first network registration.
2. Turn On the Taiwan eSIM
The profile can be installed but disabled. Confirm that the line itself is switched on.
On iPhone
- Open Settings.
- Select Cellular or Mobile Service.
- Choose the Taiwan or NoveSIM line.
- Enable Turn On This Line.
On Samsung
- Open Settings.
- Select Connections.
- Open SIM Manager.
- Turn on the Taiwan eSIM.
On Google Pixel
- Open Settings.
- Select Network & Internet.
- Open SIMs.
- Select the travel eSIM.
- Enable Use SIM.
3. Select the Taiwan eSIM for Mobile Data
One of the most common problems is that the phone continues using the home SIM for mobile data.
On iPhone
- Open Settings.
- Select Cellular.
- Tap Cellular Data.
- Select the Taiwan eSIM.
On Samsung
- Open Settings.
- Select Connections.
- Open SIM Manager.
- Under Mobile Data, select the Taiwan eSIM.
On Google Pixel
- Open Settings.
- Select Network & Internet.
- Open SIMs.
- Choose the Taiwan eSIM as the preferred mobile data SIM.
Turn off WiFi after making the change and test a webpage or map application.
4. Enable Data Roaming on the Travel eSIM
Data Roaming normally needs to be enabled because the eSIM connects through supported partner networks.
This setting should be turned on only for the Taiwan eSIM. Keep roaming disabled on your home SIM unless you intentionally want to use your regular operator abroad.
| SIM Line | Data Roaming |
|---|---|
| Taiwan travel eSIM | Enabled |
| Home SIM | Disabled |
Enable roaming on iPhone
Settings → Cellular → Taiwan eSIM → Data Roaming
Enable roaming on Samsung
Settings → Connections → Mobile Networks
Select the travel eSIM when the phone asks which line you want to configure.
Enable roaming on Google Pixel
Settings → Network & Internet → SIMs → Taiwan eSIM → Roaming
5. Disable Automatic Mobile Data Switching
Automatic switching can move mobile data back to your home SIM if the phone believes the travel connection is temporarily weaker.
This may cause:
- No internet when roaming is disabled on the home SIM.
- Unexpected roaming charges.
- Unstable switching between two networks.
- The appearance that the eSIM is not working.
On iPhone
Open Cellular Data and disable Allow Cellular Data Switching.
On Android
Look for settings such as:
- Automatic Data Switching.
- Switch Mobile Data Automatically.
- Backup Calling and Data.
- Data During Calls.
The wording depends on the manufacturer and software version.
6. Check the APN
If the phone shows signal bars but applications do not load, the APN may be missing or incorrect.
Use the following settings when manual configuration is required:
| Field | Value |
|---|---|
| Name | NoveSIM or Taiwan |
| APN | data.esim |
| Username | Leave empty |
| Password | Leave empty |
APN on iPhone
Open:
Settings → Cellular → Taiwan eSIM → Cellular Data Network
Enter data.esim in the Cellular Data APN field. The menu may not be visible if the profile manages the APN automatically.
APN on Samsung
Open:
Settings → Connections → Mobile Networks → Access Point Names
Create a new APN if required, save it and select it as the active profile.
APN on Google Pixel
Open:
Settings → Network & Internet → SIMs → Taiwan eSIM → Access Point Names
7. Turn Airplane Mode On for 30 Seconds
Toggling Airplane Mode forces the phone to disconnect and register again on the available mobile network.
- Turn Airplane Mode on.
- Wait 30 seconds.
- Turn Airplane Mode off.
- Wait several minutes.
- Test mobile data with WiFi disabled.
This is particularly useful after changing the APN, data line or roaming settings.
8. Restart the Phone
A restart can resolve incomplete network registration and apply newly saved mobile settings.
After restarting:
- Confirm the eSIM is still enabled.
- Confirm it remains selected for mobile data.
- Check that Data Roaming is still on.
- Turn off WiFi and test the connection.
9. Keep Network Selection on Automatic
Automatic network selection is normally the best setting. The eSIM should connect to an available supported partner network.
Manual network selection may cause problems if you choose an operator that is visible but not included in your plan.
Use manual selection only when:
- Automatic registration repeatedly fails.
- Customer support provides a specific operator.
- You have already completed all standard settings checks.
10. Move to an Area With Better Signal
Signal can be weaker in locations such as:
- Airport basements.
- Underground metro stations.
- Train tunnels.
- Mountain roads.
- Remote coastal areas.
- Buildings with thick walls.
Move outdoors or closer to a populated area before concluding that the eSIM has failed.
eSIM Shows No Service in Taiwan
If the phone displays No Service, the profile has not registered on an available network.
Check the following:
- The travel eSIM is turned on.
- You are already inside Taiwan.
- The phone is carrier-unlocked.
- Network Selection is set to Automatic.
- The plan is still within its validity period.
- The eSIM has not been installed on another device.
- Airplane Mode is off.
Allow several minutes for the first connection, especially immediately after landing.
eSIM Has Signal but No Internet
Signal bars without working internet usually point to a data configuration issue.
The most likely causes are:
- The Taiwan eSIM is not selected for mobile data.
- Data Roaming is disabled.
- The APN is incorrect.
- Automatic switching has selected the home SIM.
- The plan has no remaining data.
- The validity period has ended.
Test the connection with WiFi turned off. Otherwise, the phone may continue using WiFi and hide whether the eSIM is functioning.
eSIM Is Installed but Not Activated
Installation only adds the profile to your phone. The eSIM may still need to connect to an included Taiwanese network before activation is completed.
After arrival:
- Enable the eSIM.
- Select it for mobile data.
- Enable Data Roaming.
- Keep network selection on Automatic.
- Wait several minutes.
Do not repeatedly install or remove the profile while waiting for activation.
eSIM Worked and Then Stopped
If the connection worked previously, check whether:
- The data allowance has been fully used.
- The plan validity has expired.
- The phone switched back to the home SIM.
- You entered a temporary weak-signal area.
- A software update changed the APN or SIM preferences.
- The daily high-speed allowance has been reached.
Unlimited-Style Plan Is Suddenly Slow
A slow connection does not necessarily mean the eSIM has stopped working.
NoveSIM unlimited-style plans provide 1GB of high-speed data during each 24-hour period. After the daily high-speed allowance is consumed, the speed may be reduced until the next 24-hour reset.
Reduced speed may still support:
- Messaging.
- Basic maps.
- Light browsing.
- Email without large attachments.
Video streaming, large downloads and hotspot use may become difficult until the high-speed allowance resets.
How to Check Whether Your Data Is Used Up
Your phone’s internal data counter can provide an estimate, but it may not match the eSIM billing period exactly.
Check for high usage from:
- Video streaming.
- Cloud photo backups.
- Automatic application updates.
- Personal Hotspot.
- Video calls.
- Social media video uploads.
If the allowance is exhausted, a new plan is required.
Can You Top Up the Same Taiwan eSIM?
NoveSIM plans cannot normally be topped up or extended using the same QR code. When the allowance or validity expires, purchase and install a new eSIM profile.
You need WiFi or another working internet connection to complete the new installation. Buy and install the replacement before travelling into an area without connectivity.
Personal Hotspot Is Not Working
If mobile internet works on the phone but not through hotspot, check:
- The Taiwan eSIM is selected for mobile data.
- The plan permits hotspot use.
- The APN is set to data.esim.
- Battery Saver is not restricting tethering.
- The connected device is not downloading large updates.
Restart both devices and recreate the hotspot connection if necessary.
WhatsApp Is Not Working With the Taiwan eSIM
A data-only travel eSIM does not change your WhatsApp number. WhatsApp should continue using the number already registered in the application.
If messages do not send:
- Test whether ordinary webpages load.
- Confirm mobile data is working.
- Disable WiFi and test again.
- Restart WhatsApp.
- Check whether background data is restricted.
Do not register WhatsApp again unless you intentionally want to change the account number.
Calls and SMS Are Not Working
NoveSIM plans are data-only. They do not include:
- A Taiwanese telephone number.
- Traditional mobile calls.
- Standard SMS messages.
Use WhatsApp, Viber, Messenger, FaceTime or another VoIP service for internet calls.
Your home SIM may remain active for calls and SMS, but your regular operator may charge roaming fees.
The QR Code Says It Has Already Been Used
This message often means the eSIM has already been installed successfully.
Check the SIM settings for an existing travel profile. It may appear under a generic label such as Secondary or Business.
Do not delete the existing profile or continue scanning the QR code. Configure the installed eSIM instead.
Should You Delete and Reinstall the eSIM?
No. Do not delete the eSIM during normal troubleshooting.
Many QR codes are valid for one installation only. If you remove the profile, the same code may not work again.
Before considering removal, check:
- Mobile data selection.
- Data Roaming.
- APN.
- Automatic switching.
- Network registration.
- Remaining data and validity.
Delete the profile only when customer support specifically instructs you to do so.
Can You Move the eSIM to Another Phone?
Travel eSIM profiles usually cannot be transferred freely between devices. The installation code may be tied to the first successful download.
Do not remove the eSIM from the original phone and attempt to install it on another device without contacting support.
iPhone Troubleshooting Summary
| iPhone Setting | Required Configuration |
|---|---|
| Turn On This Line | Enabled |
| Cellular Data | Taiwan eSIM |
| Data Roaming | Enabled on travel eSIM |
| Cellular Data Switching | Disabled |
| Network Selection | Automatic |
| APN | data.esim |
Android Troubleshooting Summary
| Android Setting | Required Configuration |
|---|---|
| Travel eSIM | Enabled |
| Preferred SIM for mobile data | Taiwan eSIM |
| Data Roaming | Enabled on travel eSIM |
| Automatic data switching | Disabled |
| Network Selection | Automatic |
| APN | data.esim |
Information to Send Customer Support
If the eSIM still does not work after completing the checks, provide clear information so the issue can be investigated faster.
Include:
- Your order number.
- The destination where you are currently located.
- Your phone make and exact model.
- Whether the eSIM appears installed.
- Whether it shows signal bars or No Service.
- A screenshot of the SIM settings.
- A screenshot of the APN.
- The network name shown by the phone.
- Confirmation that Data Roaming is enabled.
Do not include or publicly share the complete QR code or activation details.
Related Articles
- How to Activate a Taiwan eSIM
- How to Install a Taiwan eSIM
- Taiwan eSIM for iPhone
- Taiwan eSIM for Android
- How to Use an eSIM in Taiwan
FAQ
Why is my eSIM not working in Taiwan?
The most common reasons are that the eSIM is not selected for mobile data, Data Roaming is disabled, automatic switching is enabled or the APN is incorrect.
What APN should I use for a Taiwan eSIM?
Use data.esim when manual APN configuration is required. Leave the username and password empty.
Why does my eSIM show signal but no internet?
Check the active mobile data line, Data Roaming and APN. Signal bars confirm network registration but not necessarily a working data configuration.
Why does the eSIM show No Service?
The phone may not have registered on a supported network. Confirm that you are in Taiwan, the line is enabled and Network Selection is set to Automatic.
Should Data Roaming be enabled?
Yes. Enable Data Roaming on the travel eSIM because it connects through supported partner networks. Keep roaming disabled on your home SIM.
Should I delete and reinstall the eSIM?
No. Do not delete it during troubleshooting because the QR code may be valid for one installation only.
Why is my unlimited Taiwan eSIM slow?
NoveSIM unlimited-style plans include 1GB of high-speed data per 24-hour period. Speed may be reduced after that allowance is used until the next reset.
Can I top up the same Taiwan eSIM?
NoveSIM plans cannot normally be topped up on the same QR code. Purchase and install a new eSIM when the allowance or validity ends.
Final Recommendation
If your eSIM is not working in Taiwan, begin with the basic settings rather than deleting the profile. Confirm that the eSIM is enabled, selected for mobile data and allowed to use Data Roaming.
Disable automatic mobile data switching, verify that the APN is data.esim and test the connection with WiFi turned off. If necessary, toggle Airplane Mode for 30 seconds and restart the phone.
Signal conditions can vary inside tunnels, underground areas and remote mountain regions, so test again in an open or populated location. Keep the eSIM installed throughout troubleshooting because its QR code may not be reusable.