Australia’s mandatory merger control regime commenced on 1 January 2026. Targeted amendments to the regime took effect on 16 September 2026. While the changes are refinements rather than a redesign, they have important consequences for companies considering acquisitions, minority investments and other strategic transactions.
Schedule 4 of the Treasury Laws Amendment (Strengthening Accountability for Tax Adviser Misconduct and Other Measures) Act 2026 (Act) amends the Competition and Consumer Act 2010 (Cth) (CCA) to address three practical issues in the operation of the mandatory merger control regime: the consequences of failing to notify a transaction, the meaning of control and associates, and the expiry of merger approvals where completion is delayed.
Unnotified acquisitions are no longer automatically void
Under the previous framework, an acquisition that met the mandatory notification thresholds but was not notified to the ACCC was automatically void at law. This applied even where the failure to notify was inadvertent or the transaction did not raise substantive competition concerns.
Under the amended framework, failure to notify no longer automatically voids a transaction. Instead, the ACCC has six years to apply to the Federal Court for an order declaring the acquisition void. The Court may declare the acquisition void unless it believes it is “undesirable”, for example because unwinding the transaction would significantly prejudice innocent third parties or be impracticable. In determining whether to make a voiding order or any other orders for divesture sought by the ACCC, the Court must not have regard to:
- whether the acquisition would or could, in all circumstances, have the effect, or be likely to have the effect of substantially lessening competition in any market;
- whether the acquisition would or could, in all circumstances, result, or be likely to result, in a benefit to the public;
- whether a benefit to the public would or could, in all the circumstances, outweigh the detriment to the public that would result, or be likely to result, from the acquisition;
Those matters may nevertheless be relevant to the ACCC’s decision whether to seek a voiding declaration.
The definitions of control and associates have been refined
The original framework assessed control in acquisitions of shares by reference to section 50AA of the Corporations Act 2001 (Cth), as modified by section 51ABS(2) of the CCA. The application of that test was not always clear because it relied on a broad and largely untested provision. The amendments focus the inquiry on whether the acquirer has the real and practical ability to determine the outcome of the target’s financial and operating decisions, either alone or together with one or more associates (joint control).
The Act also introduces section 51ABSA of the CCA to address uncertainty under the previous framework about the meaning of “associates”.
For the purposes of joint control, the new definition narrows the Corporations Act concept of “associates”. A person will be an associate of another person if they are in the same corporate group, have entered into a relevant agreement for the purpose of controlling or influencing the target entity’s financial and operating policies, or are acting in concert for that purpose.
Importantly, these changes—particularly the concept of joint control—bring Australia’s approach to control more closely into line with European merger control principles, making it easier for businesses to apply a more consistent approach to global transactions.
ACCC approvals can be extended where completion is delayed
An ACCC approval is valid for 12 months. Previously, if a transaction did not complete within that period, the parties were required to file a new notification.
The amendments allow the ACCC to extend an approval for up to six months, with more than one extension available where appropriate. In considering an extension application, the ACCC must assess whether there is a reasonable explanation for the delay, whether market conditions have materially changed since clearance was granted, and whether a fresh notification would be more appropriate.
This provides greater flexibility for transactions affected by lengthy regulatory approvals, complex separation arrangements, financing conditions or delayed overseas completion steps. Those issues can be particularly relevant in consumer goods transactions involving significant physical assets, manufacturing facilities, change of control consent requirements, licensing arrangements or product registrations across several jurisdictions.
Practical tips for businesses
- Failure to notify remains a serious compliance risk: Although an unnotified acquisition is no longer automatically void, completing a notifiable transaction without clearance remains unlawful, remains subject to the regime’s standstill obligation and may expose the parties to civil penalties and enforcement action. The ACCC continues to monitor mergers and acquisitions through public sources and market intelligence. Businesses should assess notification requirements for each transaction, including whether the cumulative acquisition rules apply.
- Assess practical influence and control: Consider whether board rights, veto rights, shareholder arrangements or coordinated decision-making give an investor, alone or together with another party, practical influence over the target.
- Monitor the expiry of ACCC approval: If completion may occur more than 12 months after approval, seek an extension early and before the approval becomes ineffective.
If you have any questions about how these amendments may affect your business, please contact Addisons’ Competition/Antitrust & Consumer team.