Australians have an unusual habit of paying off their mortgages much faster than borrowers in most other rich nations, a valuable trait that gives households a safety buffer were the economy to slow sharply.

Around half of all borrowers are ahead on mortgage payments, the Reserve Bank reported today, a level only reached by Canada among developed nations.

"In this way, many households have a buffer that they could temporarily draw on to stay current on their loan repayments if their incomes were to fall," the central bank said in its semi-annual report on financial stability.

This peculiar feature of the local market was noted by officials from the International Monetary Fund in the country recently to assess the local banking system. It was one reason the IMF awarded the banks top marks in a series of stress tests, setting them apart from many of their global peers.