The Reserve Bank of New Zealand has confirmed that retail banks will have to lift their core funding ratio to 75% by January next year.
Last year, the bank deferred the increase by six months after Europe's debt crisis created serious concerns about the ability of the banks to raise money.
The global financial crisis prompted the Reserve Bank to force banks to strengthen their financial position.
That included lifting the core funding ratio, which is made up of local deposits and long term wholesale funding of more than a year, and reduce the reliance on short term foreign funding.
The bank is also considering limiting the build up of risk during credit booms, and reducing the risk to taxpayers from propping up failed banks.