These systems settings can be configured in Head Office > Maintenance.
Inherit parent item’s tax rate
Use modifier item’s tax rate
|Determines the source of modifier tax rate.|
Determines whether zero-cost modifiers contribute towards the set number of free modifiers on a modification group.
For example, a customer orders a pizza with the following modifiers: BBQ swirl ($0), tomato ($0.5), and extra pepperoni ($2). The allowed quantity free is 1.
When the setting is Yes, BBQ swirl will be the free quantity as the setting includes items that are already free. When the setting is No, tomato will be the free quantity as it's the cheapest modifier that isn't already free.