The surprise 50-basis-point increase in the Reserve Bank of Australia’s cash rate will almost certainly be passed through to mortgage holders which would mean repayments on a $500,000 debt increasing by $133 a month – as banks work to restore net interest margins squeezed when rates hit rock bottom.

But since many borrowers are ahead on repayments, or have taken out fixed-rate loans, it could take some time before many households feel the pinch.