The Queensland suburb of Kingston leads the nation when it comes to homeowners falling behind on mortgage repayments.
Figures from ratings agency Fitch show Kingston, in the Logan area south of Brisbane, tops the list of the worst 20 postcodes in Australia for mortgage delinquencies, by both the value of missed payments and number of households struggling to make repayments.
As of September 2014, 26 out of 1,000 borrowers in its sample of Kingston mortgageholders were at least 30 days behind in their repayments.
"The increase in unemployment since September 2013 in the regions located south and southeast of Brisbane may have impacted mortgage performance," Fitch said in its report.
Queensland was the worst performing state, with five of the worst 20 performing postcodes by number of bad mortgages, and eight of the worst 20 postcodes by value.
Victoria had six of the worst 20 performing postcodes by number, and NSW five when measured by value.
All states had improved in the six months since the end of March, partly because of an improving property market and steady interest rates, but Queensland showed the smallest improvement.
Four regions in the state's south east - Ipswich, Logan, Gold Coast East and Gold Coast West - have been among the worst performing regions for mortgage repayments since March 2011.
Fitch analyst James Zanesi said a higher rate of mortgage defaults could reflect weaker sociological and economic conditions.
"People who live on the west side of Sydney, northwest of Melbourne, or in the Logan area may be commuters who have a lower income and are more sensitive to expenses," he said.
But the rate of mortgage delinquency could also indicate a high degree of property speculation, where borrowers had taken on big loans that they couldn't pay back.
"In the Gold Coast, the delinquencies are usually due to highly leveraged investment properties or speculators," Mr Zanesi said.
Worst 10 postcodes for late mortgage payments, by number:
1 - Kingston, Qld (postcode 4114)
2 - Cessnock, NSW (2325)
3 - Goodwood/Montrose, Tas (7010)
4 - Aldinga, SA (5173)
5 - Green Valley, NSW (2168)
6 - Laidley, Qld (4341)
7 - Mount Isa, Qld (4825)
8 - Hillside, Vic (3037)
9 - Budgewoi, NSW (2262)
10 - Corio, Vic (3214)