You are not able to set a country as default in the field Tax Country for all sales orders.
Reproducing the Issue
- Go to the Sales Orders work center.
- Select New Sales Order under common task.
- Select View All button.
- Select the Items tab.
- Select the Taxes sub-tab
- The tax country should always be ABC (ABC represents the country ID).
You cannot set country ABC by default as tax country.
The determination of Tax code and country depends upon the parties selected in the sales order (i.e. Seller and Ship-to) and the Tax Authorities maintained.
This is the expected system behavior.
KBA , AP-SLO , Sales Order Processing , How To