Co-authored by Chloe Ferreira
From 1 July 2025, Australia has started the transition to a scheme involving mandatory notifications of certain mergers and acquisitions. The mandatory notification system will come into full effect from 1 January 2026 and will have major implications for how businesses plan and execute transactions.
Merger Control Provisions Before 1 July 2025
The Competition and Consumer Act 2010 (Cth) prohibits mergers or acquisitions that would have the effect, or likely effect, of substantially lessening competition in any market in Australia.[1] However before 1 July 2025 there was no requirement for parties to notify the ACCC’ of a proposed merger, or await clearance before completing a transaction.[2] The regime relied on enforcement after transactions, including the ACCC seeking injunctive relief[3] or divestiture orders[4] through the Federal Court of Australia. Nonetheless an informal notification process was available for businesses to obtain assurance from the ACCC that a proposed acquisition would not substantially lessen competition.[5]
Critics of this regime have noted that this reactive approach with limited enforcement has allowed problematic mergers to go ahead without proper scrutiny.[6] The lack of mandatory pre-merger review or powers to suspend/stop/pause a merger has been viewed as increasingly out of step with international best practices and ‘no longer fit for purpose’.[7]
Key Changes from 1 July 2025
Owing to changes under the Treasury Laws Amendment (Mergers and Acquisitions Reform) Act 2024 (Cth), from 1 July 2025, Australia will transition to a merger control system that introduces requirements for all businesses considering acquisitions that meet certain thresholds. The features of the new system include:
- a voluntary notification scheme until 31 December 2025;
- a mandatory notification scheme from and including 1 January 2026;
- proactive assessments of all proposed mergers by the ACCC; and
- making merger information publicly available
- Transition to a Mandatory Notification Scheme
Between 1 July and 31 December 2025, a voluntary notification phase will operate to allow businesses and advisers to become familiar with the new framework. Submitting notifications during this period will not be mandatory, but they will be assessed in a similar manner as those lodged from and including 1 January 2026. The ACCC has committed to providing non-binding guidance during this phase to assist parties in understanding the likely application of the new rules.
From 1 January 2026, parties will be required to notify the ACCC where the transaction meets defined thresholds, based on either party size or transaction value. These thresholds are intended to be set by regulation and may consider annual Australian turnover, asset values, or other financial criteria.
The four main threshold tests are:
- Combined acquirer/target turnover test: If the sum of the GST turnover of all parties, shares and assets is $200 million or more; [8]
- Acquired shares or assets turnover test: If the sum of the GST turnover of the acquired shares and assets is $50 million or more; [9]
- Accumulated acquired shares or assets turnover test: This involves two tests and relates to circumstances where there are creeping or serial acquisitions; [10]
- Transaction value test: If the transaction value of the acquisition is $250 million or more.[11]
Other tests include the very large corporate group turnover test[12] and small acquisition test.[13]
Notification will be mandatory, and parties will not be able to complete the transaction until the ACCC has issued a clearance or the statutory review period has expired.[14] Failure to notify about a notifiable merger will be an offence and could result in an automatic voiding of the acquisition[15] and monetary penalties.
- ACCC Assessment and Approval
The reforms transition Australia’s merger review process from a post-merger enforcement model to a proactive decision-making approach led by the ACCC. Upon notification, the ACCC will conduct a formal assessment within a set period—initially 30 business days, extendable in certain circumstances.[16] In addition, the ACCC may:
- grant clearance unconditionally;
- grant conditional clearance subject to undertakings; or
- prohibit the merger if it’s likely to substantially lessen competition.
Notifications must be made in writing, accompanied with the relevant fee[17] and provide certain information under a prescribed form.[18]
- Public Disclosure of Merger Information
A notable transparency feature of the new regime is the mandatory publication of merger notifications and outcomes.[19] The ACCC must maintain a public register containing details of notified mergers, including the identities of the parties, the nature of the transaction, and the ACCC’s decision or progress on the matter. This approach aims to promote confidence in the regulatory process, facilitate market feedback, and deter strategic under-reporting.
Takeaways – What This Means for Businesses
Key impacts include:
Extended Deal Timelines
Under the new legislation, all transactions above the thresholds will require upfront ACCC approval. Businesses will need to factor in clearance timelines and align other milestones. Early engagement with lawyers is recommended to avoid and minimise delays.
Higher Transaction Costs
There will be increased costs associated with preparing merger notifications, responding to ACCC requests, and engaging with regulators and third parties. These should be budgeted early and built into the transaction process.
Confidentiality and Public Disclosure
The ACCC may publish details of any proposed mergers, which could affect sensitive negotiations and investor confidence, by exposing deals to early media scrutiny or stakeholder opposition.
Strategic Planning and Contractual Risk
Businesses must reassess merger and acquisition strategies, considering the new notification thresholds and potential regulatory reviews. The new system may affect valuation, structure, and risk allocation in transaction documents.
Legal Exposure and Penalties
Failure to notify about a merger above the threshold, or attempt to close a transaction before ACCC clearance is obtained, could result in significant penalties.
Smaller Deals May Still Be Caught
Even if your transaction falls below the financial thresholds, they may still be subject to ACCC scrutiny if they raise competition concerns.
Need help navigating the new merger regime?
If your business is considering a transaction, Coleman Greig Lawyers can assist you in assessing notification requirements, preparing submissions, and managing ACCC engagement. With significant changes having commenced on 1 July 2025, early legal guidance can help you avoid delays, reduce risk, and stay ahead of your regulatory obligations.
For tailored advice or to discuss your transaction, please contact our Commercial Services team.
[1] Competition and Consumer Act 2010 (Cth) s 50 (‘CCA’).
[2] Explanatory Memorandum, Treasury Laws Amendment (Mergers and Acquisitions Reform) Bill 2024 (Cth) 4, [1.8].
[3] CCA ss 80 and 80AC.
[4] CCA ss 81 81A and 81B.
[5] See Australian Competition & Consumer Commission, Informal Merger Review Process Guidelines (November 2017).
[6] Australian Competition and Consumer Commission, ‘Evidence backs case for critical merger law reform’ (Media Release 8/24, 2 February 2024).
[7] The Treasury, Impact Analysis Merger Reform: A Faster, Stronger and Simpler System for a More Competitive Economy, September 2024, 19.
[8] Competition and Consumer (Notification of Acquisitions) Determination 2025 (Cth) s 1-9..
[9] Competition and Consumer (Notification of Acquisitions) Determination 2025 (Cth) s 1-10.
[10] Competition and Consumer (Notification of Acquisitions) Determination 2025 (Cth) s 1-11.
[11] Competition and Consumer (Notification of Acquisitions) Determination 2025 (Cth) s 1-12.
[12] Competition and Consumer (Notification of Acquisitions) Determination 2025 (Cth) s 1-13.
[13] Competition and Consumer (Notification of Acquisitions) Determination 2025 (Cth) s 1-14.
[14] Competition and Consumer Act 2010 (Cth) ss 51ABF and 51ABZE.
[15] Competition and Consumer Act 2010 (Cth) ss 45AZA and 77D.
[16] Competition and Consumer Act 2010 (Cth) s 51ABZI.
[17] Competition and Consumer Act 2010 (Cth) s 51ABX.
[18] Competition and Consumer Act 2010 (Cth) ss 51ABX and 51ABY, and Competition and Consumer (Notification of Acquisitions) Determination 2025 (Cth) pt 6.
[19] Competition and Consumer Act 2010 (Cth) s 51ABZZH.
