Changes to merger control regime now in effect

On 16 September 2026, legislation amending some elements of Australia’s merger control regime came into effect.

Schedule 4 of the Treasury Laws Amendment (Strengthening Accountability for Tax Adviser Misconduct and Other Measures) Act 2026 makes a number of operational refinements to the new merger control regime to help reduce legal uncertainty.

Key changes

• Making non-notified transactions that meet the thresholds voidable instead of automatically void.
• Clarifying the control exemption.
• Introducing flexibility for approved notifications that take longer than expected to complete.

The ACCC welcomes these changes. We are working on guidance which we will release shortly.

About the legislative changes

The amending Act was passed by Parliament on 10 September 2026 and received royal assent on 15 September 2026.

Details on the changes include:

Non-notified acquisitions will be voidable rather than automatically void

Where an acquisition that is required to be notified is put into effect without notifying the ACCC, the ACCC can now apply to the Federal Court for orders declaring an acquisition void, requiring divestiture or granting other remedies. The Court must not have regard to the competitive effects of the transaction when making orders. Previously, non-notification could have resulted in automatic voiding of the acquisition if it met the thresholds.

Rules on ‘control’ and ‘associates’ are clarified

New definitions clarify which interests held by associates should be considered when assessing whether a person has control. This is intended to better capture influence over a business that is likely to be competitively significant, while carving out ordinary commercial arrangements such as minority shareholder protections, financing agreements and professional advisory relationships.

Approved notifications can remain effective for longer

After a notification has been approved, parties have 12 months to put a notified acquisition into effect. However, the ACCC may extend this period by up to six months at a time where requested. This could occur where there are reasonable reasons for delays and it remains appropriate to rely on the original notification. Details of any extension must be published on the Acquisitions Register.

Register Now: Australian Competition Summit 2026

The 2026 Australian Competition Summit will be held on Thursday 15 October at Doltone House Hyde Park, Sydney. For more information see, ACCC Australian Competition Summit.

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