When mobile data doesn't work, it is a real nuisance, especially when you are out and about and without a WiFi network nearby. After all, you can forget about surfing the net. We reveal what you can do.

There are several possible reasons for mobile data not working on your smartphone – from a software error to hardware problems and a system-wide failure. In the following we explain how you can solve the problem on your own if necessary.

This is what you have to do when mobile data doesn't work

• First restart your Android smartphone or iPhone. Then try to see if your mobile data works again.
• If restarting doesn't help, turn off your phone completely. Wait a few seconds before turning the device back on.
• Make sure airplane mode is turned off . If this mode is active, mobile data will not work.
• Sometimes an activated WLAN can prevent your mobile data from working. The error is more common on older iPhones in particular. Therefore switch off the WLAN connection on your mobile phone.
• Disabled bluetooth. Just like an activated WLAN, Bluetooth can also cause problems with mobile data.
• It is possible that the problem is not with your cell phone, but with the network operator itself. In this case, check relevant websites such as allestören.de to see whether users are having increasing problems with the provider.
• Also make sure that your data volume is not already used up . Pay attention to the SMS from your mobile phone provider or find out more about your available data volume directly from them.
• Sometimes outdated firmware on your phone is also responsible for the problems. Make sure your phone has the latest software version, otherwise install it.
• Check whether your SIM card is free from damage and is correctly inserted in the SIM slot of your mobile phone. The SIM contacts are relatively sensitive and can refuse to work in the event of minor damage. Replacing it can also help.
• If everything does not help, perform a factory reset . Make a backup of your data beforehand, then reset your phone to factory settings.
• Sometimes your mobile phone has a lock from your mobile operator . In this case, SIM cards from other mobile network providers will not work. You can find out from your provider whether your mobile phone has a SIM or Netlock.

Mobile data does not work on Android 10 or 11

If you have problems with mobile data after updating to Android 10 or Android 11, it may be due to a faulty update. In this case, it can help to reset the so-called Access Point Name (APN). It works like this:

• "Settings> Network & Internet> Cellular Networks> Access Point Name".
• A list of your APNs should now be displayed here.
• Tap the menu icon and then "Reset to defaults".
• Note that the individual points can have different names depending on the mobile phone.

Not all Android smartphones have the ability to reset the APN. In this case you can define " IPv4 / IPv6" as the setting and simply leave the field blank. It may be necessary to enter the APN settings manually. You will receive the data for this from your network operator.