Australia tightens merger rules from April as ACCC thresholds expand

The new regime replaced the country’s voluntary notification system with mandatory reporting obligations for transactions that meet specified monetary or structural criteria. The notification thresholds which came into effect from 1 January 2026 applied to acquisitions involving all or substantially all the assets of a business.

Where a transaction did not involve all or substantially all of a business, in a partial acquisition, only the existing transaction value threshold of $250 million (approx. US$170 million) applied. Under this regime, notification was only required where the greater of the sum of the market value of shares and assets being acquired, and consideration received or receivable for the acquisition, was A$250 million.

From 1 April, new transaction value thresholds will apply to acquisitions that do not involve all or substantially all of a business, further expanding the scope of transactions subject to mandatory ACCC notification.

These changes split partial asset acquisitions into two categories: ‘large acquirers’ and ‘very large acquirers’. Deals involving less than all of a business’ assets will become notifiable when the acquirer group has at least A$200 million in Australian revenue and the global transaction value is at least A$200 million.

For ‘very large acquirers’, notification will be required if Australian revenue meets or exceeds A$500 million and the global transaction value is at least A$50 million. Acquisitions of all or substantially all assets will continue to be assessed under the existing monetary thresholds.

A new voting power test will also come into force on 1 April, expanding the types of share acquisitions that trigger mandatory notification even when they do not result in full control.

Ewan Robertson, an expert in national and cross-border mergers and acquisitions at Pinsent Masons, said: “Businesses that don’t reassess their transaction pipelines risk delays or potential enforcement action from the ACCC.”

“These new voting power triggers mean acquirers can no longer rely solely on traditional control tests. Even incremental share movements may now require clearance, which materially changes deal strategy,” he said.

“For large and very large acquirers, the revised thresholds will capture a wider range of transactions. Early assessment is no longer optional, but a critical step in ensuring deals go ahead."

Karena Huang, an expert in cross-border mergers and acquisitions at Pinsent Masons, said: “Merger parties should consider these notification requirements during the early stages of deals, and explicitly consider both pre- and post-completion voting power, given that voting thresholds will independently trigger reporting obligations from April.”

“For unlisted companies that are not widely held, notification will be required when an acquisition lifts an investor’s voting power from 20% or below to above 20%. For all body corporates, deals must be reported if voting power between 20% and 50% increases to 50% or more,” she said.

“Additional rules also apply to chapter 6 entities. These include mandatory notification when an acquirer with existing control increases voting power from 20% or below to above 20%, or when an investor without control before or after the deal increases its voting power from below 20% to 50% or more.”