The big four banks are losing mortgage market share

Australia’s four major banks still dominate home lending, but their grip on the mortgage market has been steadily weakening.

APRA’s August 2026 banking statistics show ANZ, Commonwealth Bank, NAB and Westpac together holding $1.83 trillion of housing loans, equivalent to 73.0 per cent of the market.

In August 2020, the same four banks controlled 77.8 per cent.

The decline has been remarkably consistent. Their combined share fell to 76.4 per cent in 2021, 75.3 per cent in 2022, 74.9 per cent in 2023, 74.6 per cent in 2024 and 73.8 per cent last year.

The majors have not been shrinking their mortgage books. Their combined housing lending has increased from $1.38 trillion to $1.83 trillion since 2020.

The problem is that everyone else has grown faster.

Australia’s total mortgage market expanded from $1.77 trillion to $2.50 trillion over the same period — growth of 41.3 per cent, compared with 32.7 per cent for the four majors.

The loss has been particularly pronounced in investor lending. The majors’ share of investor mortgages has fallen from 82.5 per cent to 76.2 per cent, while their owner-occupier share has declined from 75.2 per cent to 71.5 per cent.

Macquarie has been a major beneficiary. Its mortgage market share increased from just 2.9 per cent in August 2020 to 7.5 per cent today.

There is an important qualification. Suncorp Bank is now owned by ANZ but remains separately reported by APRA as Norfina Limited. Including Suncorp lifts the current major-bank group share to about 75.3 per cent — still below the four majors’ 77.8 per cent share in 2020.

And this is specifically a mortgage story. Over the same six years, the majors’ combined share of business lending has actually edged higher, from 69.5 per cent to 70.4 per cent.

Competition is reshaping Australian banking — but not uniformly.