There are now more borrowers “at risk” of mortgage stress, as measured by Roy Morgan, than at any time in the past decade.

Based on surveys conducted during December, the research estimates that 1.1 million owner-occupied mortgage borrowers (23.9 per cent of the total) are at risk.

The level is up from 19.4 per cent in the middle of last year, when rates started to rise, and is above the long-term average of 22.8 per cent that goes back to 2007.

The proportion of mortgage borrowers estimated to be “extremely at risk” is 15 per cent. 

Roy Morgan measures mortgage stress in two ways: borrowers are at risk if their mortgage payments are greater than a certain percentage of after-tax household income (25 to 45 per cent, depending on income and spending); and they are considered extremely at risk if the interest component of their payments is over those percentages.

The cash rate is currently 3.1 per cent, after starting to rise from 10 basis points in May last year.

Roy Morgan estimates that if rates rise another 50 bps by March, the proportion of at-risk borrowers will rise to 26.3 per cent – another 213,000 borrowers.

Roy Morgan chief executive Michele Levine said: “For the first time in this cycle of interest rate increases the proportion of mortgage holders considered at risk has increased above the long-term average and is at its highest since 2013. 

“Australia’s rising inflation level and all the indications from the reserve Bank suggest rates will increase again meets again in February and in March.”