Is a 10% discount for early payment of electricity bills and a 10% late payment fine for those who delay permissible or forbidden (halal or haram)?

The fine for delayed bill payment is usury (riba), and the distribution of sin between the Israeli company and the local company is as follows:

1. If the local company is merely an agent for providing electricity and there is no other way to obtain it except through them, then the sin falls upon the Israeli company. 2. If the local company is a commercial entity selling electricity to citizens, then the sin falls upon them. They are not permitted to impose a usurious fine on their customers, even if fines are imposed on them by the Israeli company. Rather, they must ensure their customers' payments are made through legitimate means.