Nokia Lumia 520 - I cannot send or receive text messages on my Lumia phone

  1. Restart your phone.
  2. Check the signal strength on the phone screen, and move to an area with better reception.
  3. Send a text message to your own mobile phone number. This will test your sending and receiving capabilities in one go.  
  4. Check the SMS centre number (Messaging > ... > settings > SMS centre number). If the number is missing or you expect it is incorrect, confirm the number with your network operator.
  5. If you have Multi-SIM (two SIM cards with the same mobile phone number), note that some text messages can only be received on your assigned primary SIM card.

If the previous steps do not help, insert a different operator SIM card into your phone to verify that the phone is working properly.