Answered by Sayyidi Habib Umar bin Hafiz (may Allah protect him and benefit us by him)
What should I do with interest payments that have accumulated in my bank account?
You should give the money to the poor and needy or some public project such as repairing roads, providing medication for the sick or feeding the poor. You cannot use it yourself or consider it your property. When you give it, it cannot be considered charity but you will have the reward of preserving it and using it in a way that pleases Allah.
