Australia’s big four banks are in discussions with the Reserve Bank of New Zealand about getting their systems ready for the potential introduction of negative interest rates, which the Kiwi central bank said “will become an option” early next year.

The RBNZ on Wednesday said its official cash rate will stay at 0.25 per cent until early 2021 and that further reductions in the cash rate would not be effective in lowering borrowing costs for New Zealanders at the moment.