Logging in and using an authenticator app

As per agent post, you can create IAM user and assign AdministratorAccess permission.

You can assign multiple MFA devices to root user and IAM users. See this blog post for more information.

When you log in as a Root user with MFA enabled using an authenticator app, that specific MFA device is tied to your Root account. For other people who need to access Amazon S3, they should not be using the Root account. Instead, you should create separate IAM users with appropriate permissions for each person.

Here's how to handle this situation:

1. Create individual IAM users for each person who needs access to S3
2. Assign appropriate S3 permissions to these users
3. Each user can then set up their own MFA device (authenticator app on their own phone)

When these users sign in, they'll use their own credentials and their own authenticator app for the MFA code. This is more secure than sharing the Root account, as it:

• Provides accountability (you know who performed which actions)
• Limits permissions to only what each user needs
• Prevents sharing of the Root account's MFA device
• Allows you to revoke access for specific individuals without affecting others

Multi-factor authentication is designed to be a personal security measure - the authenticator app should be on the device of the person who owns the account. Sharing MFA devices goes against security best practices and defeats the purpose of having MFA in the first place.

If you're concerned about the complexity, consider using AWS IAM Identity Center (formerly AWS Single Sign-On) for managing access for multiple users in a more streamlined way.
Sources
Registering your device for MFA - AWS IAM Identity Center
Log In Driving me crazy | AWS re:Post

"Assign appropriate S3 permissions to these users" I gave up trying to do that - made no sense. Instructions may as well be in another language.

I think I'll just give the next person the root login and I have one IAM User - setting that up nearly did my head in as well.

Thanks for your help.