Final answer:
A notice must be sent within 30 days to the customer if there are changes in banking practices, inclusion of additional names on bank cards, or abrupt changes to will.
Step-by-step explanation:
The subject of this question is Business and the grade level is High School.
According to the information provided, a notice must be sent within 30 days to the customer if there are changes in banking practices, inclusion of additional names on bank cards, or abrupt changes to will. These changes are significant enough to require immediate communication with the account holder.
For example, if a bank decides to change its fee structure or if a person's name is added to a joint bank account, a notice must be sent within 30 days to inform the customer of these changes.