How to do it...

1. From the AWS console of the master account, click on your username, and select My Organization from the drop-down menu:

2. You will be taken to the AWS Organizations console, where you will see your current account:

3. Click on the Invitations tab in the top-right of the console:

4. Click on the Invite account button. Specify the account ID (or main e-mail address) of the account to invite:

5. Once you click Invite, you will be taken to a list of invitations where you can view the status:

6. At this stage, the target/invited account will receive an e-mail notifying them of the invite:

7. Log in to the invited account and go to the My Organization link under the user menu:

8. In the AWS Organizations console, you can see the pending invite on the left:

9. Clicking on the invite, you can see its details:

10. When the invite includes all features, you will be asked to confirm your acceptance:

11. Once confirmed, you can now see the details of the organization you have joined:

12. At this stage, the master account will be notified of the accepted invite:

13. Back in the master account, you can now see the new account alongside the master: