Closing an AWS account

In March of 2022, AWS introduced the oft-requested organizations:CloseAccount API which at long last allows administrators to close AWS accounts programmatically, saving them from a tedious process that formerly involved password resets, credit cards, and phone number verification.
To close an AWS account that's a member of your organization, follow these steps:
1.Note from substrate.accounts.txt the account number of the account you wish to close
2.Make super-duper sure this is the account you wish close
3.substrate assume-role -management aws organizations close-account --account-id <account-number-noted-above>
See AWS' announcement for more information on using this API, its limitations, and your options should you wish to reopen a closed account.