What is the ruling on not paying tuition fees in public schools where payment is not obligatory, and where non-payment does not result in punishment or expulsion?

The default rule is that tuition fees in public schools must be paid by those who are able to afford them. Certain categories are exempt from this, such as the poor, orphans, and outstanding students. Whoever is not among these categories and defaults on payment while being able to afford it, must contact the relevant authority to pay what is due or to clarify their situation.