Unable to Send SMS using SNS

It might be happening because your account currently has a spending quota of $1.00 (USD) per month for sending SMS messages. This limit is set to help you test the message-sending capabilities of Amazon SNS without incurring high costs.

It's important to note that the cost of sending an SMS message varies depending on the destination country and the type of message (e.g., promotional or transactional). For example, sending an SMS to the United States might cost ≈ $0.00645 per message. With the $1 quota, you could send approximately 155 messages to the United States at this rate.

Once your spending reaches this limit, AWS will stop sending SMS messages for your account to prevent any additional charges. This is to ensure that you do not incur unexpected costs.

If you find that your messaging needs exceed this quota, you can request an increase to the SMS spending quota for your account. To do this, please open a quota increase case in the AWS Support Center, and the team will be happy to assist you.