Configure your tax rates by clicking the Add button, then entering the name and percentage. The tax rate set as default will be applied automatically when adding a new product. Tax rates marked as inactive will not appear in the product details dropdown.
You can apply up to three different tax rates to an item (product). Selecting the Use tax rate 2 option enables applying a second tax, and similarly, Use tax rate 3 allows for a third tax rate.
When using multiple tax rates, additional columns for Tax 2 and Tax 3 become available on the invoice view. Likewise, product details will have extra dropdowns for these taxes.
By default, tax applied to items is exclusive (not included in the product price). If you want tax included in the price, select the Use inclusive tax option.