I had this question a little while back so thought I’d share as it might not be so obvious where the data comes from. If you print a sales confirmation or invoice you will see a column on the end called print code. What is this?  Well this is from a field on the tax code setup.

Here is a quick overview.

D365 July 2017 Update 8 (7.0.4565.16211)

Cheers

Lachlan