What is the phone number for key bank? Phone Number of Key Bank is +1-(800)-539-2968 . Key Bank is also termed as KeyCorp, which is one of the major financial institutions of United States, based to Cleveland.What is payment address for key bank? To send your payment by check, include your payment stub and write your account number on your check's memo line. To be sure your payment is received on time, allow 7 - 10 business days before your due date. KeyBank. P.O. Box 94920. Cleveland, OH 44101-4920.What are the customer service hours? Most of the Customer Service centers operate between the hours of 8:00 AM and 5:00 PM. Please refer to your bill for the exact hours of operation of the Customer Service center in your area.What is bank customer service? A bank customer service representative is someone whose role is to provide information regarding the bank’s products and services to its customers.