To add extra security to your account you are able to do this via your Settings; Settings > Customer Service. When you access this setting you will be brought to the screen below. It details that the TM3 support team will always ask you for your client ID when you call but you have the option of applying a higher security level to your account. You can find out where your client ID is via this article.
There are three settings for you to choose from and these are shown and explained in the image below:
1. No additional Security - Standard security TM3 have.
2. 'Data' Related Security - Issues that involve data will be asked for a security word.
3. Full Security - No matter the issue you will be prompt for your security word.