Tasmanians and Queenslanders are the nation's worst for keeping up with home loan repayments.
A report from ratings agency Fitch shows just under one in a hundred mortgages in Tasmania, or 0.99 per cent, were 30 days or more in arrears at the end of March.
In Queensland it is 0.95 per cent, compared to a national average of 0.85 per cent.
At the other end of the scale came the meticulous, punctual public servants of the ACT, with a delinquency rate of just 0.46 per cent.
That is streets ahead of the next best, NSW and the Northern Territory, both with an arrears rate of 0.76 per cent.
Victoria's delinquency rate was 0.84 per cent, WA's was 0.87 per cent and South Australia's was 0.94 per cent.
The national average was down from 1.02 per cent a year earlier, with all states and territories in better shape than a year ago, aside from NT, which was steady.
Fitch said most of the 20 worst performing postcodes were in metropolitan regions, aside from the Queensland mining centre of Mount Isa.
"However, metropolitan regions overall performed better than non-metropolitan areas, especially in Western Australia, Queensland and Northern Territory where the slowdown and job cuts in the mining industry have been detrimental to mortgage performance," Fitch said.
The figures were compiled from a study of over 988,000 loans, representing about 12 per cent of all home loans in Australia, Fitch said.
Top 10 postcodes for mortgage delinquency:
1 - 4502 Petrie, Qld - 2.4pct
2 - 4341 Laidley, Qld - 2.3pct
3 - 3214 Corio, Vic - 2.3pct
4 - 4825 Mount Isa, Qld - 2.1pct
5 - 4114 Kingston, Qld - 2.0pct
6 - 2262 Budgewoi, NSW - 2.0pct
7 - 5108 Salisbury, SA - 2.0pct
8 - 3337 Melton, Vic - 1.9 pct
9 - 3976 Hampton Park, Vic - 1.9pct
10 - 6066 Ballajura, WA - 1.9pct