End User Messaging

To check your phone number's registration status in the AWS console, navigate to the AWS End User Messaging Social console and select 'Phone numbers'. In the Phone numbers section, the Status column displays each phone number's current status. For your phone number to be able to send messages, the status must show as 'Active'. If the status shows as 'Incomplete setup', you can select the phone number and click 'Complete setup' to finish the setup process.

Regarding your SNS topic configuration, yes, issues with the SNS topic ARN or access policy could potentially affect the setup. When you enable message and event publishing, the SNS topic must meet specific prerequisites. If there were configuration issues during the initial setup, this could contribute to the connection problem you're experiencing.

For retrying the connection, you can add the phone number to your existing WhatsApp Business Account through the AWS console. Go to Business Accounts and select 'Add WhatsApp phone number'. This will launch the Facebook portal where you'll log in with your Meta developer account credentials. You can then select your existing WABA and WhatsApp Business Profile to complete the phone number addition process. During this process, you'll need to verify the phone number again and configure the settings including the PIN and message/event publishing options.

Before proceeding, ensure that your phone number can receive SMS or voice OTPs and that it's not currently associated with any other WhatsApp Business Account. Also verify that your SNS topic is properly configured with the correct permissions if you plan to use it for message and event destinations.
Sources
View a phone number's status - AWS End User Messaging Social
Add a phone number to a WhatsApp Business Account (WABA) - AWS End User Messaging Social
WhatsApp calling in AWS End User Messaging Social - AWS End User Messaging Social

AWS doesn't publish a dedicated troubleshooting path for this exact Meta message. The answers below come from how the service's onboarding flow works, so treat the specifics as things to verify.

1. Checking status and retrying

In the console, go to AWS End User Messaging → Social messaging → Business accounts in ap-southeast-1. Open the WABA and look at its Phone numbers tab. If the number isn't listed, or is listed without a healthy status, the AWS side of the association never completed, even though Meta shows the account as linked.

From the CLI, which often shows more than the console:

aws socialmessaging list-linked-whatsapp-business-accounts --region ap-southeast-1
aws socialmessaging get-linked-whatsapp-business-account --id <waba-id> --region ap-southeast-1
aws socialmessaging get-linked-whatsapp-business-account-phone-number --id <phone-number-id> --region ap-southeast-1

Check registrationStatus on the account and look for the phone number entry. CloudTrail is also worth a look: search for AssociateWhatsAppBusinessAccount events around the time you clicked "Add phone number". A failed call there will usually include the actual error message.

There's no standalone "retry registration" button. The standard way to retry is to run the onboarding flow again (question 3).

2. Could the SNS setup have caused it?

Yes, plausibly. The event destination is validated as part of the same association step that registers the number, so a bad topic can make the whole step fail. Check that:

• The topic is in ap-southeast-1, and the ARN is complete and correct.
• The topic's access policy allows the service to publish:

  {
    "Effect": "Allow",
    "Principal": { "Service": "social-messaging.amazonaws.com" },
    "Action": "sns:Publish",
    "Resource": "arn:aws:sns:ap-southeast-1:<account-id>:<topic-name>",
    "Condition": { "StringEquals": { "aws:SourceAccount": "<account-id>" } }
  }

• If the topic uses SSE with a customer-managed KMS key, the key policy also grants kms:GenerateDataKey* and kms:Decrypt to social-messaging.amazonaws.com. An AWS-managed aws/sns key won't work for this.

Two other common culprits are worth ruling out at the same time:

• The PIN. If two-step verification was ever set on that number, the 6-digit PIN you enter must match the existing one. A mismatch makes registration fail on Meta's side. You can reset or disable two-step verification in WhatsApp Manager under the phone number's settings.
• The number itself. It must not still be active in the WhatsApp or WhatsApp Business mobile app, or registered with another provider.

3. Re-running the signup

Yes. Fix the SNS policy first, and the PIN if needed. Then click Add WhatsApp Business Account again, and in the Meta embedded signup choose your existing WABA and the existing phone number rather than creating new ones. On return to the AWS console, enter the PIN and the corrected SNS topic, then add the number. If you'd rather avoid risking the SNS step again, you can leave event publishing off during this attempt and add the event destination afterward.