If you do not have sufficient funds available in your KeyBank Hassle-Free Account to cover a transaction, this may cause the transaction to be declined. However, based on how the payment transaction was presented to KeyBank and whether the merchant requested available balance verification, it is possible a payment could be posted to your account resulting in an overdraft situation. In the rare case that your account is overdrawn, KeyBank will not charge you an overdraft or NSF (non-sufficient fund) fee.