Following are some of the common reasons why the messages don’t get delivered:

• Sending messages to an invalid number like a landline number
• Mobile switched off or out of network
• The destination number has opted out
• The Message subscription on the destination number has expired (e.g.- The customer having 1:1 communication and suddenly a message is not delivered).
• Spam Detected- Too many messages sent using long codes, like bulk or campaign (We suggest either Shortcode or Toll-free number).
• The number has opted out of receiving messages
• Number is overwritten
• The end-user’s mobile plan does not support SMS
• The number is no longer valid
• Prepaid subscription for SMS expired
• The sender ID entered is not in the correct format, not SMS-enabled, or not assigned to your account
• Network issues at the carrier end
• Spam detected- SMS filtered
• Invalid SMS Content- blank SMS or SMS exceeds the characters limit of 1600 for messages