Why my organization not create

Hello.

According to the documentation below, the default number of organizations that can be used with Amazon WorkMail is 100.
If you have created more than 100 organizations in your AWS account, creation may fail due to quota restrictions.
https://docs.aws.amazon.com/workmail/latest/adminguide/workmail_limits.html

If you have created fewer than 100 organizations, there may be some restrictions on your AWS account, so I recommend contacting AWS Support under "Account and billing."
"Account and billing" inquiries are free of charge.
https://console.aws.amazon.com/support

This error message "ORGANIZATION_LIMIT_FOR_ACCOUNT_EXCEEDED" indicates that you've reached the maximum number of organizations allowed for your AWS account, even if you believe you have zero organizations.

There are several possible explanations:

1. Hidden or inactive organizations: You might have organizations in non-active states (Failed, Creating, Impaired, Inactive, Requested, or Validating) that still count against your quota. Even failed organization creation attempts might count toward your limit.

2. Eventual consistency delays: If you recently deleted an organization, there could be a delay in the system recognizing that previous organizations have been deleted. AWS uses eventual consistency, meaning changes can take time to propagate across all systems.

3. Account limitations: For new or minimally used AWS accounts, your actual quota value may be lower than the default AWS quota values. This is a common issue with newer accounts.

4. Region-specific organizations: Check across all AWS regions as organizations are region-specific.

To resolve this issue:

1. Check the console for any organizations in non-active states.

2. If you recently deleted an organization, wait longer (up to an hour or more) for the system to fully process the deletion.

3. Try launching a free tier EC2 instance and wait 15-20 minutes before retrying. This sometimes helps establish account credibility with AWS systems.

4. If the issue persists, contact AWS Support. Even without a paid support plan, AWS can assist with account-related issues like this through the Account and Billing support option.
   Sources
   Create WorkMail Organization Fails | AWS re:Post
   AWS Control Tower cannot create an account because you have reached the limit on the number of accounts in your organization. | AWS re:Post