Overdraft and Returned Item Fees are assessed when you try to use more money than there is available in your account—so, more money than your available balance reflects.
Until a deposit is made to cover all outstanding transaction amounts, your available balance will be negative, and you will incur a fee of $36 each time a transaction is paid with negative funds or returned as unpaid. (SunTrust will not charge a fee on any transactions that are less than $5 and we limit Overdraft and Returned Item fees to six per day.) If your balance remains negative for five consecutive business days, you may be charged an additional one-time Extended Overdraft Fee.
If you incur an Overdraft or Returned Item Fee, we’ll make it easy to see in Online Banking and Mobile Banking, along with the transaction that caused it.
Here's an example from Online Banking:
Note: Overdraft Fees may be assessed on checks, recurring debit card transactions and ACH items. Also, if you have accepted Overdraft Coverage, ATM and one-time debit card transactions may be assessed an Overdraft Fee.