What is the ruling on depositing money in banks, and what is the ruling on money deposited in interest-based banks for previous years and its profits?

A Muslim is not permitted to deposit money in interest-based (usurious) banks, even without earning interest. This is because it involves engaging in prohibited usury and cooperating in sin, especially since Islamic banks exist. Therefore, the wife must obey her husband in transferring money from interest-based banks to Islamic banks.

As for usurious interest, it is not permissible to benefit from it or leave it in the banks. Rather, it must be taken and spent on charitable causes and for the benefit of Muslims, with the intention of getting rid of unlawful money.