I got Access Denied while adding phone number for AWS End User Messaging SMS

Hello,

Our Accounts team is best tooled to assist with these matters. I recommend creating a case with them to take a closer look into this. Here's where you can create your case:

http://go.aws/support-center

In the meantime, I suggest reading through these resources for a possible solution:

https://aws.amazon.com/premiumsupport/knowledge-center/sns-sms-spending-limit-increase/

&

https://docs.aws.amazon.com/sns/latest/dg/channels-sms-originating-identities.html

If these aren't quite what you're looking for, you're welcome to look into these additional help options for further assistance:

http://go.aws/get-help