Australia's Mandatory Merger Control 2026, When to Notify the ACCC, How to Apply for a Waiver, Practical Steps for M&A Teams

Australia’s mandatory merger control regime, which commenced on 1 January 2026, represents the most significant reform to competition law mergers in Australia in decades. For the first time, parties to qualifying acquisitions must notify the Australian Competition and Consumer Commission (ACCC) before completing their transaction, and they are legally prohibited from closing until clearance is granted or a waiver obtained. This suspensory merger control framework in Australia replaces the former voluntary, informal clearance system and demands that every M&A team, board of directors and private equity sponsor reassess their deal timelines and compliance processes.

This guide delivers the practical tools that in-house counsel and corporate advisers need: a step-by-step explanation of ACCC merger notification triggers, a waiver application walkthrough, and board-level checklists designed for immediate use.

Executive Summary and Decision Snapshot

The 2026 changes mean that any acquisition meeting prescribed monetary thresholds or involving targeted classes of transactions must be notified to the ACCC before completion. The regime is suspensory, closing before clearance is unlawful and exposes parties to significant penalties. The ACCC reviews notifications in defined statutory phases, with the earliest Phase 1 decision possible on business day 15.

Key takeaways for deal teams:

• Mandatory filing. If your transaction meets the notification thresholds set out in the Competition and Consumer (Notification of Acquisitions) Determination, you must notify the ACCC before closing. There is no option to proceed informally.
• Suspensory effect. Completion before ACCC clearance or a granted waiver is prohibited. Factor statutory review periods into every deal timetable from the letter of intent stage.
• Waivers are possible but not automatic. The ACCC may waive the notification obligation or the suspensory requirement on specified grounds, but applicants must provide detailed justifications and supporting evidence.

Industry observers expect the regime to add several weeks, and in complex cases several months, to Australian deal timelines. Early engagement with competition counsel and, where appropriate, pre-notification discussions with the ACCC are now essential components of M&A compliance in Australia 2026.

Background: What Changed in 2025–26 and Key Legislative Dates

Australia’s previous approach to merger control was unusual among advanced economies. Under the former regime, notification to the ACCC was entirely voluntary. Parties could seek informal clearance, apply for formal authorisation on public-benefit grounds, or simply proceed without engaging the regulator at all. The ACCC could only challenge a completed acquisition by seeking court orders under section 50 of the Competition and Consumer Act 2010 (Cth), a process widely regarded as slow, expensive and difficult to enforce after the fact.

The Australian Treasury’s 2023 Competition Review identified this voluntary framework as a significant weakness. Following extensive public consultation and the passage of amending legislation, the Government introduced a mandatory, suspensory notification regime for acquisitions on or after 1 January 2026. Further refinements to notification thresholds and targeted-class definitions took effect on 1 April 2026, following the release of an updated Notification Determination.

Why the Change Matters for Deals

The shift from voluntary to mandatory merger control in Australia 2026 has three immediate consequences for transaction planning. First, deal timetables must now incorporate statutory review periods that cannot be shortened by agreement between the parties. Second, acquirers bear the burden of preparing and filing a complete notification, including market-share data and competitive-effects analysis, before any binding completion can occur. Third, the ACCC’s enforcement powers have been materially strengthened: the regulator can block transactions, impose conditions, or seek penalties for non-compliance without first needing to obtain a court order to unwind a completed deal.

When to Notify the ACCC, Triggers and Merger Thresholds Australia

Not every transaction triggers the ACCC merger notification obligation. The Notification Determination sets out specific monetary thresholds, control tests and targeted-class rules that determine whether a filing is required. The critical first step in any M&A compliance process in Australia is applying these tests to your specific transaction.

Monetary Thresholds

The notification obligation is triggered where the transaction meets either of the following monetary tests, as set out in the Notification Determination:

Red flag, stop and check: If either the acquirer has A$500 million or more in Australian revenue and the target (or combined entity) has A$50 million or more, or if the transaction value exceeds A$250 million, the notification obligation is likely triggered. Seek competition law advice immediately.

Control Versus Influence

The regime captures acquisitions of a controlling interest in a body corporate or assets of a business. “Controlling interest” includes the acquisition of shares or assets that confer the ability to determine the policy of a company, whether directly or through voting power, board composition or contractual arrangements. Acquisitions of minority stakes that confer material influence, but not control, may also be caught where they fall within a targeted class.

Deal teams should not assume that a sub-50% acquisition is automatically excluded. The ACCC has indicated it will look at the practical effect of the transaction on competitive dynamics, not merely the percentage of shares acquired.

Targeted Classes and Exemptions

Certain sectors and transaction types are designated as “targeted classes” under the Notification Determination. Transactions falling within a targeted class may be notifiable even if they do not meet the general monetary thresholds. Early indications suggest that targeted classes include:

• Supermarkets and grocery retail. Acquisitions by major grocery retailers, reflecting heightened competition concerns in concentrated markets.
• Digital platforms and technology. Acquisitions by large digital platform operators, particularly serial or “creeping” acquisitions of nascent competitors.
• Healthcare and pharmaceuticals. Transactions involving hospitals, pathology providers or pharmaceutical manufacturers where market concentration is already elevated.
• Telecommunications and media. Consolidation among licensed carriers or media operators.

Conversely, certain categories of acquisition may be exempt or subject to simplified notification requirements, for example, internal corporate restructures that do not change ultimate economic ownership, or certain transactions already subject to equivalent review by another Commonwealth regulator (such as the Foreign Investment Review Board).

Three-step decision checklist, do I need to notify?

1. Calculate the acquirer’s Australian turnover, the target’s Australian turnover, and the total transaction value. If any threshold is met, proceed to step 2.
2. Determine whether the acquisition confers a controlling interest or falls within a targeted class. If yes, proceed to step 3.
3. Check whether an exemption applies (internal restructure, equivalent regulator review, etc.). If no exemption applies, you must notify the ACCC before closing.

How the ACCC Review Works, Phases, Timing and Suspensory Effect

Once a notification is filed, the ACCC reviews the transaction through defined statutory phases. Understanding these phases, and the suspensory merger control rules that apply throughout, is essential for managing deal certainty and stakeholder expectations.

Timelines: ACCC Phases, Business Days and Suspensory Effect

The merger filing process at the ACCC proceeds as follows:

1. Pre-notification (optional but recommended). Parties may engage the ACCC before filing to discuss the scope of the notification, identify likely competition concerns and narrow the information requirements.
2. Phase 1 review. Once the ACCC accepts a notification as complete, a statutory clock begins. The ACCC may issue a clearance decision from business day 15 onwards. Many straightforward transactions, those raising no material competition issues, are expected to be cleared during Phase 1.
3. Phase 2 review. If the ACCC identifies potential competition concerns, it may extend the review into Phase 2 for a more detailed investigation. Phase 2 involves market inquiries, requests for further information and, in some cases, the proposal and negotiation of remedies or conditions.
4. Decision. At the end of its review, the ACCC will either clear the transaction (unconditionally or subject to conditions), or decline clearance.

Suspensory rule: The acquisition must not be completed at any point before the ACCC issues its decision. Closing in breach of the suspensory obligation is a contravention of the Competition and Consumer Act, regardless of the merits of the transaction.

What to Do During ACCC Review

During the review period, deal teams should maintain a separate, clean-room approach to integration planning. Avoid exchanging competitively sensitive information between merging parties beyond what is strictly necessary for the notification. Continue to operate as independent competitors until clearance is formally granted. The ACCC has publicly signalled that it will scrutinise gun-jumping, premature integration or coordination, as a serious compliance matter under the new mandatory merger control Australia 2026 framework.

How to Apply for a Notification Waiver, ACCC Process and Grounds

The ACCC has the power to waive either the notification obligation itself or the suspensory requirement. A notification waiver from the ACCC is not automatic and must be justified with clear evidence. The waiver mechanism exists to address situations where strict compliance with the filing or waiting requirements would be disproportionate, unnecessary or harmful.

Grounds on which a waiver may be sought:

• No realistic prospect of competition concern. The transaction is clearly benign, for example, it involves the acquisition of a business in a market where the acquirer has no presence.
• Urgency or financial distress. Delay caused by the suspensory period would result in serious commercial harm, for instance, where a failing-firm defence is available or an urgent capital injection is required.
• Administrative overlap. The transaction is already subject to equivalent merger review by another regulator (e.g., FIRB or a foreign competition authority) and separate ACCC notification would be duplicative.
• Error or technical deficiency. The notification obligation was triggered by a technical or administrative error, and the acquisition does not substantively affect competition.

Practical Drafting Tips

When preparing a waiver application, address each of the following in a structured submission:

1. Identify the specific waiver ground relied upon and explain how it applies to the facts.
2. Provide supporting evidence, market-share data, financial statements, third-party expert reports or statutory declarations as appropriate.
3. Explain the harm that would result from compliance with the notification or suspensory requirement, including any quantifiable financial impact or risk to third parties.
4. Propose a realistic timeline for completion and explain why the waiver would not prejudice competition or the public interest.

Common Reasons Waivers Are Granted or Refused

Early indications suggest the ACCC will take a pragmatic approach where the competition risk is clearly low, but it will refuse waiver applications where market concentration is borderline or where the applicant has not provided sufficient evidence. Incomplete submissions and vague claims of urgency without documentary support are the most common reasons for refusal. The likely practical effect will be that well-prepared, evidence-rich waiver applications submitted early in the deal process have the highest chance of success.

Pre-Notification Practical Checklist and M&A Due Diligence

Thorough preparation before filing an ACCC merger notification is the single most effective way to reduce review times and avoid requests for further information that can stall a deal. The following checklist identifies the key documents and data sets that deal teams should assemble before engaging the ACCC.

Pre-Notification Liaison with the ACCC, When and How

The ACCC encourages parties to engage in pre-notification discussions, particularly for complex transactions or those likely to raise competition concerns. Pre-notification discussions are not mandatory, but they offer significant practical advantages: parties can narrow the scope of information required, identify potential issues early and, in some cases, negotiate the terms of a conditional clearance before the formal clock starts.

Industry observers expect that parties who invest in pre-notification engagement will experience materially shorter Phase 1 timelines compared with those who file without prior dialogue.

Confidentiality Considerations and Public Filings

Parties should note that the ACCC may publish a public register of notifications received, including basic transaction details. Requests for confidential treatment of commercially sensitive information should be made at the time of filing and clearly justified. Deal teams should plan their public disclosure and ASX announcement timetables around the assumption that notification details may become public.

Practical Step-by-Step Timeline for M&A Teams

Integrating the ACCC’s mandatory merger control process into a standard deal timetable requires careful coordination across legal, finance and commercial workstreams. The following roadmap sets out a recommended sequence from letter of intent through to closing.

Board Approvals and Minute Language to Reduce D&O Risk

Board resolutions authorising the acquisition should expressly reference the mandatory notification requirement and confirm that the company will not complete the transaction until ACCC clearance (or an applicable waiver) has been obtained. Suggested minute language:

“The Board notes that the proposed acquisition is subject to mandatory notification to the Australian Competition and Consumer Commission under the Competition and Consumer Act 2010 (Cth). The Board resolves that the Company shall not complete the acquisition, and shall not take any step that would constitute completion, until such time as the ACCC has granted clearance or an applicable waiver has been obtained. The Company Secretary is directed to confirm compliance before any completion steps are taken.”

Consequences and Enforcement Risk, Penalties for Not Notifying the ACCC

Failing to notify the ACCC where required, or closing a transaction before clearance is granted, exposes parties to severe enforcement consequences. The Competition and Consumer Act provides for a range of remedies, and the ACCC has publicly indicated that it will take a robust approach to compliance under the new regime.

Key penalties and remedies include:

• Civil pecuniary penalties. Substantial financial penalties may be imposed on both the corporate entity and, in some circumstances, individual officers who were knowingly concerned in the contravention.
• Injunctions and interim orders. The ACCC may seek urgent court orders to prevent completion or to freeze integration steps pending investigation.
• Divestiture and unwind orders. Where a transaction has been completed without notification, the court may order divestiture, forcing the acquirer to reverse the acquisition entirely.
• Criminal liability for false or misleading statements. Providing false or misleading information in a notification or waiver application carries criminal penalties.
• Reputational damage. ACCC enforcement actions are publicly reported and can materially affect market confidence, share price and future deal-making credibility.

Remedies and Interim Orders

The ACCC has confirmed that it will actively use interim hold-separate orders where it has reason to believe a notified transaction poses serious competition risks. These orders prevent the merging parties from integrating operations during the review period. Breach of an interim order is itself a contravention and attracts additional penalties.

Directors’ Duties and Practical Questions for Boards

Directors bear personal responsibility for ensuring their company complies with the mandatory merger control regime. Under the Corporations Act 2001 and the Competition and Consumer Act, directors who authorise or permit a transaction to close without required ACCC clearance may face personal liability.

Board-level compliance checklist:

• Has a threshold assessment been completed? Ensure competition counsel has provided a written opinion confirming whether notification is required.
• Is the deal timetable merger-control compliant? Verify that the transaction documents include a condition precedent requiring ACCC clearance before completion.
• Are records being maintained? Document all competition law advice received, all ACCC correspondence, and all board discussions relating to the notification.
• Is D&O insurance adequate? Confirm that the company’s directors’ and officers’ insurance covers competition law contraventions and regulatory investigations.
• Has gun-jumping risk been addressed? Confirm that no competitively sensitive information has been exchanged and that no integration steps have been taken before clearance.

Comparison: Before and After Australia’s Mandatory Merger Control 2026

Timeline of Key Regulatory Dates

For further context on international commercial law considerations that may intersect with Australian merger control, particularly for cross-border transactions, consult the relevant practice area guides. Deal teams requiring access to competition lawyers in Australia can search the Global Law Experts lawyer directory. To learn more about the Global Law Experts network, visit the About page.

Sources

1. Australian Competition & Consumer Commission (ACCC), Mergers and Acquisitions
2. ACCC, Merger Process Quick Guide (December 2025)
3. Australian Treasury, Competition Review / Mergers
4. Allens, Merger Control Guide
5. Herbert Smith Freehills / HSF Kramer, Treasury Updates Merger Rules
6. Foreign Investment Review Board, Merger Control Regime Interaction
7. BDO Australia, How to Prepare for Australia’s Merger Control Regime