What is the bank fee charged when an account balance falls below zero called?

An overdraft fee is a charge associated with an account balance falling below zero or with a bank covering a payment despite insufficient funds. The exact rules depend on the account agreement and local regulation.

An overdraft occurs when withdrawals, card payments, checks, or other transactions exceed the available balance. Some banks decline the transaction, while others pay it and create a negative balance. A linked savings account or approved overdraft line may cover the shortfall under separate terms.

Overdraft fees are distinct from nonsufficient-funds fees, although banks may use different names and policies. In some jurisdictions, customers must opt in before certain one-time debit-card or ATM overdraft services can be provided.