"The one certainty, however, is that you will hear about instances where we haven’t got it right for our customers," Mr Hartzer wrote. "Some of these examples will be uncomfortable to hear and will no doubt disappoint you, as they have me."

"They show that over the last decade there have been too many cases where we have not treated customers with the respect they deserve. "They also show that we have more work to do to make our systems and processes more reliable, to make sure we’re getting it right for our customers every time, and importantly that we learn from the things that go wrong," the email said. Westpac is due to face scrutiny in this round of hearings, to take place in Melbourne this week and next, over its treatment of car loan customers, and problems in providing unsuitable credit card limit increases.

Loading The major banks have been asked to hand over information about specific customers' cases, and lenders expect the commission to look at case studies where customers have been treated poorly. As banks brace for the further hit to their public reputations, Mr Hartzer said the examples did not represent "our purpose or who we are as an organisation". He vowed Westpac's approach during the royal commission would be one of "transparency, integrity and empathy". "We will acknowledge where we’ve got it wrong, and the steps we’ve taken to put right and make sure that the issues don’t recur," Mr Hartzer said. The public scrutiny of Westpac's car financing is expected to include case studies of individuals who were given inappropriate car loans. Unlike some other issues to be pored over by the commission, problems with banks' car lending have received relatively little public attention.