In Islamic Banking, there are some banking practices are strictly prohibited by Islamic law.
some principles / laws adopted by the Islamic banking system are:

1. Payment of loans with different values ​​of the value of loans with predetermined values ​​are not allowed. 

     2.  Funders should also share the profits and losses as a result  
          of institutional efforts to borrow funds. 

     3.  Islam does not allow the "make money from money".  
          Money is only a medium of exchange 
          and not a commodity because it has no intrinsic value. 

     4.  Gharar element (uncertainty, speculation) is not allowed. 
          Both sides must know all too well
          the results they would get from a transaction. 

     5.  Investments should only be given to businesses that are not 
          forbidden in Islam. Businesses such as liquor should not be  
          funded by Islamic banking.