Westpac New Zealand expects the Kiwi dollar to trend back up towards the end of 2015, as the rest of the global economy gains some steam.
The retail bank said its annual cash earnings rose 13 percent to $864 million, reflecting across-the-board growth.
The bank, which will release its statutory earnings later this year, said net operating income for the year ended September rose 3 percent to almost $2.07 billion.
Bad debt charges fell sharply to $26 million, compared with $117 million the year earlier.
Acting chief executive David McLean said the significant improvement reflects the strength of the New Zealand economy, though he saw some risks on the horizon.