How to setup a Tax code applied at supplier level and automatically applying at the invoice level. ?

Summary:

Tax Rule - Tax code applied at supplier level was not automatically applying at the invoice level.

Content (required):

Hello

I was wondering if you can share with me how to enable a tax rule - where the tax code is applied at the supplier level and the applied the tax rate automatically at the invoice level.

Thanks for your help

Version (include the version you are using, if applicable):

R13

Code Snippet (add any code snippets that support your topic, if applicable):