Cannabis in America is still federally illegal, even in states with legal medical marijuana programs. Therefore, state-legal medical marijuana transactions are mostly conducted with cash. This cash is not allowed to be deposited in a bank, because The Federal Reserve regulates state-chartered member banks. Being unable to bank puts business owners in the cannabis space in a quandary on how to conduct business like other merchants.
Similarly, using apps like Square or Venmo -which is a PayPal company- are risky. If the customer or merchant is caught using either for a cannabis-related transaction, his account will be shut down.
Full Article / Source: www.forbes.com