This article explains why the Tax Type, Tax Rate and Line Tax could be missing on any Inventory, Order Entry, POS, Job Costing, etc., related transactional documents.
The image below indicates how these fields usually display as expected, but for some reason, they may not be available.

The following steps explain how to resolve this issue:
1. Check on the Inventory Defaults | Entry Options screen if the option below is on 'Calculate Tax Per Document', as opposed to 'Calculate Tax Per Line'.
2. If you need to enter a Tax Type and view the other line tax fields on the document, select the 'Calculate Tax Per Line' option below and save the change.
