My Contact Information Doesn't Show Tax Preference

My Contact Information Doesn't Show Tax Preference

Hi Folks,
My largest customer is tax exempt. 
I do not see the "Tax Preference" in the Other Details part of the Edit Contact page (as shown on your video).

Can you tell me how to access this? I am just realizing that I can make it a preference. My contact has existed for years, not a new contact. This option doesn't show up on a New Contact page either.

Thanks.