Reg E limits your liability for unauthorized or fraudulent electronic activity that occurs on your account if you notify the bank within certain deadlines. The complete text of Reg E is rather lengthy. Here is a summary:
You are liable for unauthorized activity that occurs on your account after you discover it but fail to alert the bank.
Tell us your name and account number. Provide clear details to help us identify the transaction(s) in question, such as date, dollar amount and the description.
We will investigate your claim. If we take more than 10 business days to complete the investigation, we will adjust your account for the amount you think is in error so that you may have use of the money during the remainder of our investigation. These provisional funds may be removed depending upon the outcome of our investigation.