When are invoices issued, and when are they due?

Recurring invoices are issued on the issue date the school picks itself (the 25th by default) through a daily check — not through a button somebody has to remember. The due date is that issue date plus the school's payment window, seven days by default.

Outside that cycle, manual invoices can be created at any time: a new student's registration, teaching materials, or a pack sold mid-month. Invoices never cross branches — a family with children at two branches receives two invoices.