Bonnar said two-thirds of TSB Bank and Kiwibank customers rated doing business with a New Zealand-owned company as a key benefit.
Local bank customers were also less likely to be paying monthly account fees, as a result, they were more likely to feel the bank's fees were reasonable, he said.
"It's unusual to have three winners in one category. However, all three deserve the recognition and we congratulate them on an outstanding achievement."
It was the second year in a row that TSB bank received the top award.
TSB Bank chief executive Kevin Murphy said it was pleased to have the highest customer satisfaction score of all the banks.
"Being recognised by the public for our exceptional customer service, amongst much larger competitors, tells us that our efforts to satisfy our customers remain a cut above the rest."