Australia's mandatory merger regime stopped three deals in its first nine months. The latest was Insurance Australia Group's proposed A$1.35 billion purchase of RAC Insurance, which the Australian Competition and Consumer Commission opposed on Sept. 23 after an in-depth Phase 2 review. Yet ACCC data show the system waving through about 95% of the deals it formally assesses within weeks.

That split matters for buyers across Asia. Since Jan. 1 every deal above the notification thresholds must be cleared by the ACCC before it can close. Bidders from Japan, Singapore and Hong Kong now have to price in a fixed review timetable, filing fees and, in concentrated markets, a real chance of being blocked.

IAG and the Other Blocked Deals

The ACCC found that IAG's acquisition would substantially lessen competition in motor vehicle insurance and in home and contents insurance in Western Australia, according to the regulator's statement, which IAG released to the ASX. RAC Insurance leads both markets in the state under the RAC WA brand. After the deal, IAG would have held roughly 55% to 65% of Western Australian motor insurance and 50% to 60% of home and contents cover, the ACCC said.

ACCC Chair Gina Cass-Gottlieb said the deal would bring "a significant increase in market concentration." The regulator said IAG was likely to be a stronger competitor in the state without the acquisition. It found too little evidence to support separate concerns about IAG restricting rivals' access to smash repairers.

It was IAG's second rejection for the same deal. The ACCC had opposed it in December 2025 under the old informal system, and IAG then refiled under the new law. The insurer plans to lodge a public benefits application, the next stage of the regime, Insurance Business Australia reported. In Queensland, by contrast, the regulator approved IAG's A$855 million purchase of RACQ Insurance in 2025, according to Business News Australia.

The two earlier blocks, both listed by law firm Gilbert + Tobin in its review of the regime's first half, were smaller. On June 30 the ACCC opposed Coles' acquisition of a supermarket lease in Kalgoorlie, the first deal stopped under the new law, and Coles has sought Tribunal and judicial review. On Aug. 7 the regulator opposed MicroStar's purchase of keg-pooling rival Konvoy, having rejected a behavioral undertaking offered in June.

Remedies are also on the table. In June the ACCC cleared Ampol's acquisition of EG Australia on condition that it sell 41 retail fuel sites, up from the 19 Ampol first offered, Gilbert + Tobin said.

What the ACCC Data Show

Most deals never come close to that level of scrutiny. In the year to June 30, which includes six months of voluntary filings before the regime became mandatory, the ACCC received 444 matters: 158 notifications and 286 applications for a waiver from notification, according to ACCC data summarized by law firm Holding Redlich on Sept. 22.

Gilbert + Tobin's review found that 115 notifications were cleared at Phase 1 in the year to June 30, or 95% of completed determinations, and 6 were referred to Phase 2. Of 244 waiver applications decided from January to June, 230 were approved and 14 denied. Median review times were 17 business days for Phase 1 and 13 for waivers, and 92% of decisions were made within 20 business days. The ACCC had promised that about 80% would be.

The mix has surprised the regulator. Before the regime began, the ACCC forecast 8.3 waiver reviews and 27.9 Phase 1 reviews a month. Through April 30 it was averaging 38 waiver applications and 8.9 Phase 1 filings a month, according to law firm Squire Patton Boggs, which published its analysis in May. Dealmakers are choosing the cheaper, quicker waiver route where they can: the fee is A$8,300, against A$56,800 for a Phase 1 notification.

Phase 2 is where the costs rise. Fees run from A$475,000 to A$1.595 million depending on deal size, Squire Patton Boggs said, and a Phase 2 review can take up to 90 business days, according to Business News Australia. Gilbert + Tobin counted nine Phase 2 referrals by mid-August. One, Trescal's purchase of TR Calibration, lapsed in July because the Phase 2 fee was not paid on time.

Large Deals Are in the Queue

The filings are not limited to small local purchases. Notified deals ranged from under A$10 million to more than A$10 billion, and the largest group by value, 28 transactions, sat between A$1 billion and A$5 billion, Holding Redlich said. Financial and insurance services, manufacturing, and professional and technical services were the most active sectors.

The ACCC's Phase 2 docket includes cross-border deals that Asian investors follow. The Saipem and Subsea7 combination and a Zoetis deal involving Neogen were among matters still under review in mid-August, according to Gilbert + Tobin, alongside Vets Central's purchase of a veterinary clinic.

The next test is IAG's public benefits application. Once it is lodged, the ACCC has 50 business days, subject to extensions, to decide whether the deal's claimed benefits to Western Australian customers outweigh the loss of competition it has already found. Coles' challenge at the Competition Tribunal is the other case that will show how far the regulator's decisions hold.