The federal government has introduced a mergers reform bill that includes a mandatory notification system and a focus on serial acquisitions.

Treasurer Jim Chalmers says it will make the system “faster, stronger, simpler, more targeted and more transparent” and will allow the Australian Competition and Consumer Commission to focus on the minority of mergers that cause concern.

Mergers above set monetary thresholds will need to be flagged with the ACCC and approved before going ahead, replacing current voluntary arrangements.

Dr Chalmers says a merger will be examined if the Australian turnover of the combined businesses is above $200 million and the business or assets being acquired have local turnover above $50 million or a global transaction value above $250 million.

Mergers involving a business with Australian turnover of more than $500 million buying a smaller business or assets with local turnover above $10 million will also be examined.

To target serial acquisitions, mergers by businesses with turnover above $200 million where the cumulative Australian turnover from acquisitions in the same goods or services over three years is at least $50 million – or $10 million if a very large business is involved – will be captured.

Dr Chalmers says monetary thresholds will be reviewed 12 months after taking effect.

The ACCC says at present it is notified of only a small proportion of the estimated 1000 to 1500 mergers each year, and about 93% of voluntarily notified deals are assessed on a confidential basis.

“This marks a significant milestone in the process of reforming Australia’s merger laws,” commission chair Gina Cass-Gottlieb said.

The laws will take effect from January 1 2026, subject to the bill passing parliament, but parties will be able to start using the new regime voluntarily from July next year.