The answer is yes, interest expense is an operating expense for a bank. 

This is because it is an expense that is directly related to the bank’s day-to-day operations.

Banks need to borrow money to lend it to their customers, and interest expense is the cost of that borrowing. 

Without interest expense, banks would not be able to operate. 

Moreover, interest expense is a significant cost for banks, and it can have a significant impact on their profitability.

If interest rates rise, the cost of borrowing for banks also increases, which can reduce their profitability.  

Therefore, it is important for banks to accurately classify interest expense as an operating expense to calculate their operating income or profit. 

In addition to interest expenses, banks also incur other expenses, such as salaries, rent, and utilities.