Is it permissible to leave employment at an interest-based bank through an early retirement program that generates more money, or is one obligated to suffice with resignation, which entails less money?

Working in usurious banks is forbidden (haram), as the worker is either a direct participant or a collaborator in sin and transgression. It is obligatory to leave such work immediately. It is not permissible for this employee to participate in the optional retirement system due to its inclusion of uncertainty (gharar) and usury (riba).

As for the financial entitlements upon resignation: if the employee was aware of the prohibition from the beginning of his work, it is not permissible for him to benefit from any of these entitlements. Rather, he must take them and spend them on charitable causes for poor and needy Muslims, or on general charitable causes such as building mosques and hospitals. He may take from it what suffices him if he or his family are poor and in need.

However, if the employee was not aware of the prohibition, he may benefit from the entitlements. If he became aware of the prohibition and continued working, he may only take the entitlements for the period he worked before he became aware of the prohibition.