A private school made the tuition fees payable in installments, for example, the first month is one thousand dinars, the next month is one thousand dinars, and the last month is one thousand dinars.

And if you are late in paying the last month, the last installment becomes two thousand dinars.

So is this increase for delaying the last month's payment considered riba?

It is not allowed, as for this, yes, it is definitely not allowed.

It is not allowed that if you delay the one thousand, it becomes two thousand, no, it is not allowed.

If you delay, they go and file a complaint against you, they do not give you the certificate.

This is their right. We say, we won't give you the certificate unless you pay us our money, while you have already paid them two thousand in the first place.

Okay, but as for the issue of one thousand becoming two thousand, no, this is not permissible.