Australia's New Merger Control Regime: Early Lessons for Dealmakers and Investors

Australia's merger control framework has fundamentally changed.

Since 1 January 2026, acquisitions meeting prescribed notification thresholds must generally be notified to the Australian Competition and Consumer Commission (ACCC), unless an exemption applies or a notification waiver is granted. The former largely voluntary clearance system has been replaced by a mandatory and suspensory regime in which the ACCC is the first-instance decision-maker for notifiable acquisitions.

For businesses, investors, and transaction teams, the significance extends beyond competition law. Merger control can now affect deal structure, transaction timetables, due diligence, contractual protections, and execution strategy from the outset.

After more than eight months of operation, several practical lessons are emerging.

What Dealmakers Should Consider Early

Before signing a transaction, parties should consider:

• Notification thresholds: Does the transaction require mandatory ACCC notification?
• Acquisition history: Do earlier acquisitions affect the cumulative thresholds?
• Regulatory timing: How does ACCC clearance interact with financing, foreign investment approval, and other regulatory approvals?
• Notification pathway: Is formal notification required, or could a notification waiver be appropriate?
• Transaction documents: Who carries the risk of delay, remedies, or refusal?
• Information readiness: Is the material needed for the regulatory process available early enough?

Understanding the Notification Thresholds

Australia's regime contains several notification thresholds.

At a high level, an acquisition may require notification where the parties have combined Australian revenue of at least $200 million and either the target has Australian revenue of at least $50 million or the global transaction value is at least $250 million. A separate threshold applies where the acquirer group has Australian revenue of at least $500 million and the target has Australian revenue of at least $10 million.

There are also cumulative thresholds aimed at serial or "creeping" acquisitions involving the same or substitutable goods or services over a three-year period. Since 1 April 2026, additional rules have applied to certain asset acquisitions and changes in voting power, including some transactions that do not result in outright control. Exemptions also apply.

The practical lesson is straightforward: notification analysis should occur before the transaction structure and timetable become difficult to change.

The Regime Is Moving Many Transactions Relatively Quickly

Mandatory notification does not necessarily mean prolonged regulatory review.

In April, the ACCC reported that its average Phase 1 approval time during the first three months of the regime was 18 business days and that waiver decisions averaged 11 business days. More recently, the ACCC said in September that approximately 90% of mergers were being determined within 20 business days, surpassing its original goal of around 80%.

Phase 1 itself can run for up to 30 business days, with business day 15 being the earliest point at which the ACCC can approve a notified acquisition. Matters requiring deeper examination may proceed to Phase 2, which can run for up to 90 business days, subject to extensions.

For straightforward transactions, the regime may therefore operate efficiently. But even a relatively short regulatory period can materially affect a transaction involving financing deadlines, competing bidders, foreign investment approval, or other regulatory conditions.

Following an approval, an acquisition generally cannot proceed until 14 calendar days after the ACCC’s reasons are published, allowing time for an application to the Australian Competition Tribunal for review.

Where a transaction may raise competition issues, early engagement can also become part of the timetable. The ACCC encourages pre-notification engagement and recommends contacting it at least four weeks before formal notification where potential competition concerns exist.

Notification Waivers Can Be Useful — But Are Not an Automatic First Step

A notification waiver removes the obligation to formally notify an acquisition that would otherwise require notification.

The ACCC says the mechanism is intended for suitable transactions that do not raise material risks to competition or consumers. It is not intended to operate as a preliminary step for every transaction. In August 2026, the ACCC updated its waiver guidance based on its experience since commencement, including guidance on suitability, early discussions, timing, and publication on the acquisitions register.

A waiver may therefore offer an efficient pathway for appropriate acquisitions. An unsuccessful application, however, can add time and cost if formal notification is ultimately required.

Transaction Documents Need to Allocate Merger Control Risk

Mandatory clearance has direct implications for transaction documentation.

Where ACCC approval is required, agreements may need to address:

• ACCC clearance as a condition precedent.
• Responsibility for notification and regulator engagement.
• Cooperation and information-sharing obligations.
• Responsibility for regulatory fees.
• Whether the purchaser must offer or accept remedies.
• Long-stop dates and termination rights.
• Allocation of regulatory risk between the parties.

These are commercial issues, not merely drafting issues. The agreed position determines who carries the risk if the ACCC requires concessions, extends its review, or ultimately does not approve the acquisition. In a competitive sale process, the regulatory profile of a bidder can itself become part of transaction certainty.

Serial Acquisitions and Buy-and-Build Strategies Need Particular Attention

The cumulative thresholds mean some acquirers must look backwards as well as forwards.

Previous acquisitions involving the same or substitutable goods or services during the preceding three years may become relevant when determining whether a proposed acquisition must be notified. Certain previous acquisitions are excluded from accumulation under the rules.

This is particularly relevant to private equity sponsors, consolidators, and corporate groups pursuing buy-and-build strategies. Fund managers and portfolio companies should maintain reliable records of prior acquisitions, relevant revenues, assets, and products rather than reconstructing that history each time another target arises.

Competition analysis increasingly forms part of portfolio strategy, not simply individual deal execution.

Regulatory Preparation Should Run Alongside Due Diligence

Merger notifications can require information concerning the parties, relevant products and services, customers, suppliers, competitors, revenues, transaction rationale, and previous acquisitions. Targets may also need to provide customer and competitor contacts and transaction documents. That information should be assembled alongside legal and financial due diligence rather than after signing.

Internal transaction material also deserves care. Board papers, investment committee documents, and strategy materials describing competitors, consolidation opportunities, or market positioning may become relevant to the ACCC's assessment.

The process also has a public dimension. Information about notified acquisitions and waiver determinations is published on the ACCC's acquisitions register, while specific processes exist for claiming confidentiality over commercially sensitive information.

For cross-border transactions, merger control may also sit alongside FIRB, ASIC, or ASX requirements, sector-specific approvals, taxation, and foreign regulatory processes. The transaction timetable should therefore reflect the critical regulatory path, not treat each approval separately.

Below the Threshold Does Not Mean Outside Competition Law

Mandatory notification and substantive competition risk are different questions.

The ACCC can investigate acquisitions below the notification thresholds where it considers that an acquisition may substantially lessen competition. Similarly, a notification waiver removes the obligation to notify but does not disapply the substantive prohibition in section 50 of the Competition and Consumer Act 2010 (Cth).

Parties should therefore distinguish between two questions:

• Must the transaction be notified?
• Does the transaction create substantive competition risk?

They are related, but they are not the same question.

The Regime Continues to Evolve

The merger framework is still developing.

Updated waiver guidance was issued in August, and further legislative changes took effect on 16 September 2026, dealing with matters including non-notified transactions, the control exemption, and extensions for previously approved notifications.

Deal teams should therefore continue to test their analysis against the current legislation and ACCC guidance rather than relying on processes developed at the beginning of the year.

The Early Lessons for Dealmakers and Investors

Several practical principles are becoming clear:

• Assess notification requirements early. Do not leave threshold analysis until signing.
• Maintain acquisition history. Serial acquisition strategies may engage cumulative thresholds.
• Build regulatory timing into the deal. ACCC clearance should be coordinated with financing, FIRB, and other approvals.
• Prepare information early. Regulatory requirements can materially affect execution.
• Allocate regulatory risk expressly. Transaction documents should address delay, remedies, and approval risk.
• Consider competition risk even below the thresholds. Mandatory notification does not define the full reach of competition law.

The central change is therefore not simply procedural. Merger control has become part of transaction architecture. Businesses that identify competition issues early, maintain appropriate acquisition records, and integrate regulatory requirements into deal planning are better placed to preserve transaction momentum and manage execution risk.

How We Can Help

We advise Australian and international clients on corporate transactions, mergers and acquisitions, competition law, and regulatory strategy.

We assist with merger control analysis, transaction structuring, notification strategy, regulatory approvals, and transaction documentation, including coordination with foreign investment and other regulatory requirements.

This publication is current as at 24 September 2026 and is provided for general information only. It does not constitute legal, financial, investment or tax advice. Regulatory obligations and appropriate governance arrangements depend on the circumstances, activities and applicable legal framework of each organisation.