The country's biggest bank, ANZ, has wracked up a solid rise in its profit on the back of increased deposits and lower costs.
The net profit after tax for the six months ended March was $869 million, up 14 percent on a year ago.
The cash profit, which excludes one-off charges and changes in asset values was $928m, 24 percent higher than last year.
"All our business units performed well in this half due to our continued simplification of the business," said New Zealand chief executive David Hisco.
Income from normal banking activities was marginally higher at $1.53 billion, but margins were squeezed by the bank having to pay higher rates of interest to attract deposits and borrow overseas, while holding down mortgage rates to attract borrowers.
ANZ's deposits rose 7 percent, outstripping the 5 percent rise in lending, while its overheads fell and bad debts shrunk to just $40m. Its earnings from investments and money market dealings were up by more than a quarter to $514m.
Mr Hisco said the bank had simplified its business and is using technology to provide better services and improve productivity, which he expected to be reflected in a strong second-half performance.