Not one of the eight car insurance brands reviewed by the corporate regulator told customers why their premium had changed, according to a report released on Tuesday covering about 72 per cent of the Australian market.

The Australian Securities and Investments Commission read the quote and renewal documents sent out by AAMI and Suncorp Insurance, both underwritten by AAI Limited, Allianz and Territory Insurance Office under Allianz Australia, NRMA Insurance and RACV Insurance under Insurance Australia Group, along with RAC Insurance and Youi. None of the eight set out the factors that determined the price. Most put generic wording in a supplementary document. Some gave no explanation at all.

The regulator titled the report Road testing transparency in car insurance premiums. It lands against figures ASIC cites showing motor premiums rose 8 per cent in the twelve months to July 2025, while the consumer price index rose 3 per cent over the same period. Between 2019 and 2024, motor premiums rose more than 42 per cent.

ASIC also surveyed more than 2,000 drivers. Seventy three per cent could recall only a generic reason for their increase.

The survey found something else. Sixty eight per cent of policyholders never contact their insurer before a renewal goes through. Of the 31 per cent who did pick up the phone, the premium came down without any change to the cover being bought.

“That finding shows it pays to ask, with some consumers who challenged their premium increase ending up with a better deal," ASIC commissioner Alan Kirkland said. He added that "clearer disclosure will help all consumers, not just those who know how to push back.”

The same pattern runs through the payment arrangements. Paying by instalments costs between 10 and 20 per cent more than paying the annual premium in one go, and 54 per cent of customers did not know that. "A cost saving of 20 per cent can go a long way," Kirkland said. "There is no excuse why some insurers cannot communicate such a basic benefit to customers."

Sixty seven per cent of drivers renew with the same insurer each year and 40 per cent do not shop around at all. Those customers receive the increase, receive no explanation of it, and in most cases pay the higher instalment price on top. The customer who reads the renewal, rings up and argues gets a different number for the same policy.

The Insurance Council of Australia, which represents the insurers reviewed, said premiums "have been under pressure across the country due to a range of factors including escalating extreme weather costs, insurance-linked taxes, and rising repair and vehicle parts costs." ASIC's finding is not about whether those costs are real. It is that none of the eight brands put them in front of the customer being charged for them.

ASIC says it will give each insurer individualised feedback, keep watching industry practice, and take enforcement action where premium disclosures are inaccurate or misleading. Kirkland put the obligation plainly: "Insurers must ensure that the information they provide as part of a quote or renewal is accurate."

No deadline has been set for the insurers to change their renewal documents. The next renewal notice is the test.