Who has not paid, how long it has been, and a reminder that goes out in one click. The list is the point — chasing fees is a weekly job, not an annual crisis.
Sorted the way you will act on it
Defaulters by class, by term or by amount outstanding. A class teacher wants their own list; the office wants the largest balances; the committee wants the total. Same data, three readings.
Reminders from the list itself
A reminder goes to the families on the list over SMS and WhatsApp, targeted rather than broadcast to the whole school. Parents who have paid are not told they have not.
A record that it was sent
Every reminder is logged against the family, so when a parent says they were never told, the school can say when it went and to which number.