DarthSidious, you need to check if your from TWS-->Account of your "buying power" got updated or not. IB's ACH-in is free and faster than the mail deposit. Even though IB's ACH-in is not as fast Ameritrade's (who makes the transfer it available to trade by overnight), it only takes 4-8 days;--but practically just 4 business days for the US customers). It would not even cost you the cashiers checks fee + postage and the fear of losing the check in mail. Unless you are sending a small amount, the wire transfer-in is the way to go at IB.