Can I give sibling discounts or run a promo?

Yes, through discount rules the school sets itself: siblings, a discount for paying up front, students enrolled in more than one class, and a date-limited promo on the first invoice. The default is empty — with no rules, no discount is ever born quietly.

Discounts do not stack: when one invoice matches two rules, the single largest value applies. Manually typed invoices are untouched by automatic rules, so a one-off concession can be given without changing the school's rules.