Australia's banks and other smaller lenders could see their funding costs rise with one ratings agency, Standard and Poor's, placing ratings of 25 lenders on negative watch.
The agency says it is concerned about rising household debt and booming property values.
The lenders include Macquarie Group Ltd (ASX: MQG), AMP Limited (ASX: AMP), Bank of Queensland Limited (ASX: BOQ), Bendigo and Adelaide Bank Ltd (ASX: BEN) as well as MyState Limited (ASX: MYS), IMB, Cuscal and CUA.
Australia and New Zealand Banking Group (ASX: ANZ), Commonwealth Bank of Australia (ASX: CBA), National Australia Bank Ltd (ASX: NAB) and Westpac Banking Corp (ASX: WBC) had their credit ratings placed on negative watch in July, after S&P placed Australia's AAA sovereign rating on negative outlook.
S&P says its view of the banks hasn't changed.
A negative watch means there is a one-in-three chance that S&P could lower these ratings in the next two years. As S&P says, "Household debt has risen to 139% of GDP in June 2016 from 118% in 2012, coupled with an increase in property prices nationally (around 5.3% adjusted for inflation) are driving the potential increase in imbalances in the economy, in our view."
"Consequently, we believe the risks of a sharp correction in property prices could increase and if that were to occur, credit losses incurred by all financial institutions operating in Australia are likely to be significantly greater; with about two-thirds of banks' lending assets secured by residential home loans–the impact of such a scenario on financial institutions would be amplified by the Australian economy's external weaknesses, in particular its persistent current account deficits and high level of external debt."
Moody's identified five major headwinds Australia's big four banks were facing in July this year, including rising property prices.
The problem for lenders is that a lower credit rating usually means higher interest rates on their borrowings – and those could be passed onto Australian borrowers.