What is the principle adopted in analyzing transactions in Islamic banks?

Islamic banks rely in their dealings on specialized committees in Islamic economics to review their operations and ensure their compliance with Islamic Sharia. The adherence of these banks to Sharia controls varies based on the scholarly level and piety of those in charge. It is not permissible to deal with these banks absolutely unless their Sharia controls are certainly or probably present. However, if it is more likely that these controls are not present, or if there is doubt about it, then dealing with them is only permissible out of necessity or need. Despite this, dealing with Islamic banks, even if some controls are lacking, remains better than dealing with interest-based banks, which a Muslim is not permitted to deal with as long as Islamic banks exist.