"The ex-gratia payments will be capped at $500,000 per customer and means all our home insurance customers have some level of financial certainty," ANZ Australia chief executive Philip Chronican said.
"While most of our customers are already covered, this move ensures all our home insurance customers get the cover they need and in many cases may have thought they already had.
"Given we were already automatically extending our flood cover on all home insurance policy renewals, we believe this is the right decision under the circumstances."
A $2500 excess would be applied, Chronican said.