Unsuccessful message delivery could be for plenty of reasons. Please check the below reasons to determine the problem 

  • Incorrect number formats
  • Missing international codes
  • Mistyped numbers
  • Expired numbers
  • Network overload/failure
  • Absent subscriber (phone switched off)
  • Memory capacity exceeded
  • Insufficient credit
  • Illegal subscriber
  • System failure
  • Sender ID not registered
  • Restricted SMS content
  • Restricted networks/countries
  • Invalid/noncompatible SMS length


If you cannot determine the problem on your own, please reach out to [email protected] with the error code.