Tax rules are defined for different tax groups. Before a rule can be defined a Tax Group must be defined.

The following provides a detailed explanation of each of the listed fields.
Choose from the list of previously defined tax groups. A group may contain as many rules as needed.
Define a tax rule name that can identify the rule in the listings
Initially only US states are listed but additional countries will be added to the list in the near future. Check the box if the rule is to be assigned to the entire country. A country rule applies to the country selected by the payee in the billing address.
If the countrywide rule checkbox is unchecked then state specific rules may be listed. Specific state rules can be added as well as countrywide rule. In the absence of a defined state rule, the countrywide rule will be applied for default. For example: A countrywide rule of 4% is set as well as statewide rule of 2% for Alabama, 3% for Virginia and 5% for California. If the payee's state is any of the listed states, namely Alabama, Virginia or California then the respective rates will be added; otherwise, the countrywide rule will apply (a payee in Texas will pay the countrywide rule as Texas is not individually defined as an exception).