Section 4--401. When Bank May Charge Customer's Account. (1) As against its customer, a bank may charge against his account any  item  which  is otherwise properly payable from that account even though  the charge creates an overdraft. (2) A bank which in good faith makes payment to a  holder  may  charge  the indicated account of its customer according to (a) the original tenor of his altered item; or (b) the  tenor  of his completed item, even though the bank knows the item has been completed unless the bank has  notice  that the completion was improper.