Do I get charged for an SMS if it failed to reach its destination?

If your message has a status of sent, delivered or undelivered, you will be charged for the message. The message was successfully reached by the carrier and delivery is out of our control once this happens.

If your message status is marked as failed you will not be charged for the messages. This indicates that the upstream carrier did not accept the message.

For more information please refer to the articles, what does my message status mean or How to troubleshoot SMS delivery.