SMS.to partners with different carriers and network providers. These providers charge per submitted SMS message. All submitted messages from SMS.to to the local network providers are charged regardless of the status. To learn more about the different types of status, please refer to How to Check SMS Logs and Status. 


We have no interest or advantage in the occurrence of FAILED messages. Your loss is our loss, and we incur the same charges for both FAILED and DELIVERED messages. If a phone number is identified as invalid, we prevent the submission, and the message will be in status REJECTED with no charge to you. However, there is a possibility that a phone number has a valid format but is still inactive, without reception, etc.


We recommend our users to utilize SMS.to's HLR list clean-up feature to prevent FAILED messages and keeping the list of numbers clean by removing inactive numbers. To learn more about the HLR list feature, please refer to How to Use HLR or contact us to learn more about how to improve delivery for your specific use case.


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If you have any questions, please send an email to support@sms.to