Despite a High Court judgement on tax liabilities this week, Standard & Poor's has affirmed its stable outlook for the Australian owners of New Zealand's four main banks.
Although the banks are likely to make significant payments to Inland Revenue in relation to these disputes, the credit rating agency says the liabilities do not change the "core" status of the banks.
Standard & Poor's says funding or capital support from their parents would be forthcoming, if required.
A ruling was issued by the High Court in Wellington on Thursday in favour of the Inland Revenue Department against the BNZ in a $654 million tax case.
After a 13 week trial, Justice Wild found that the bank used six offshore transations from 1998 - 2005 to avoid paying $416 million. It's also liable for interest of $238 million.
Justice Wild said the transactions had no commercial rationale, logic or purpose.
Inland Revenue is seeking $2 billion in unpaid tax and interest from the four main banks, arguing they used these transactions between 1998 - 2002. All are Australian-owned.