Hi,
When you first install HikaShop, you get the wizard screen where you can enter a tax rate and name which will be used as default.
This will actually generate two things:
- a tax rate with that name and rate, which you can do via the "new" button of the screen you can access via the "manage tax rates" button of the System>Taxes menu.
- a tax rule with that tax rate selected, the default tax category selected, and the "main tax zone" of the configuration selected. You can do the same via the "new" button of the System>Taxes menu.