A record 24,546 Australian households are at risk of defaulting on their mortgage, with new research revealing a 24 per cent annual increase on the heartbreaking number.

A report on the September quarter, published by OurTop10, revealed that mortgage pressure is now spreading beyond Sydney and Melbourne into Adelaide and regional Queensland.

A default officially occurs when a borrower fails to meet their loan repayment obligations, signalling severe financial distress. 

Mortgage default risk increased in 66 of Australia’s 70 ranked postcodes, according to data compiled by Digital Finance Analytics (DFA). 

Despite quarterly growth slowing to three per cent, the market is still absorbing the impact of an 18 per cent jump in the June period. 

OurTop10 Head of Research Mansour Soltani said the slowdown offered no comfort.

“A slower quarter is not a better quarter,” he said. 

“Twenty-four thousand households at risk of defaults is a record for this series, and the pressure is now spreading from the growth corridors into Adelaide and regional Queensland.

“These figures don’t yet capture September’s rate hike, let alone this week’s, and the full impact of earlier hikes is still working its way through household budgets.”

Mr Soltani warned that the latest report was a “snippet” of the imminent “national crisis”. 

“What we’re seeing now is likely just a snippet of what will become a bigger national crisis over the next 12 months as the effects of five rate hikes start to snowball,” he said. 

“Many households have already burned through their savings buffers. The real test now is how much longer they can hold on in this economic climate.

“We’re already seeing early warning signs, with banks reporting a rise in requests for hardship arrangements this year.”

Cranbourne in Melbourne’s south east remained the highest concentration of risk in the country, with 1,364 households estimated to default. 

Blacktown in Western Sydney recorded the nation’s sharpest annual increase of 76 per cent. 

Across the states, South Australia recorded the most rapid momentum, with households at risk expanding by 13.6 per cent over the quarter and 31 per cent annually. 

South Australia’s Encounter Bay recorded the country’s largest quarterly increase, up 78 per cent from 93 to 166 households.

It was followed by Glenelg North at 52 per cent, South Plympton at 38 per cent and Pooraka at 31 per cent. 

The pressures come amid the Reserve Bank’s decision on Tuesday to lift interest rates to an 18-year high.

The RBA lifted the cash rate 25 basis points from 4.6 to 4.85 per cent, after six members of the nine person board voted to hike rates while the remaining three voted to hold.

Canstar said this hike lifts monthly repayments on a $600,000 loan with 25 years remaining by another $92.

Adding this to the four hikes already this year means repayments are $456 a month higher than in January.