Nokia Lumia 521 - I cannot connect to the internet using a mobile data connection on my Lumia phone

1. Restart your phone with SIM card inserted and retry your mobile data connection (your phone loads the settings from the SIM card).

2. Enable the mobile data connection on your phone. Go to Settings > mobile+SIM (cellular) and switch Data connection to On.

3. Check that your data roaming is activated when you are not in your home network. Go to Settings > mobile+SIM (cellular) and select data roaming options.

4. Confirm with your mobile operator that you have an active mobile data subscription (access to internet) on your SIM card.

5. On your phone or computer, try searching online to find the Internet APN settings for your mobile operator. To add your settings manually, select one of the options:

  • Go to Settings > mobile+SIM > SIM settings > SIM, and tap add Internet APN.
  • Go to Settings > access point, and tap +.