Three months into Australia’s mandatory merger control regime, the early data confirms what experienced practitioners anticipated – deal timelines are longer, preparation requirements are more demanding, and mid-market businesses that assumed they were below the regulatory radar need to reconsider that assumption.
Key takeaways:
- Australia’s mandatory merger notification regime commenced on 1 January 2026, replacing the previous voluntary system and aligning Australia with international best practice by requiring ACCC clearance before completion for transactions meeting prescribed thresholds.
- In the regime’s first three months, the ACCC received 50 merger notifications and 108 waiver applications – a pace that demonstrates how broadly the new rules are being applied across the transaction market.
- Mid-market transactions that previously proceeded without regulatory engagement are now subject to formal notification requirements, adding time, preparation cost, and complexity to deal processes that parties had not historically needed to plan for.
- Preliminary competition analysis, proactive ACCC engagement, and realistic timetable construction are no longer optional steps in an M&A process – they are foundational requirements from the moment a potential transaction is identified.
Why the Voluntary System Could No Longer Stand
Australia’s previous merger regime was an outlier among developed economies. Under the old framework, merger review by the ACCC was largely voluntary – parties could choose to notify, seek informal guidance, or proceed without any regulatory engagement at all, subject to the ACCC’s residual power to challenge transactions in the Federal Court. In practice, this created a system that depended heavily on the goodwill and self-assessment of deal participants, and that gave the ACCC limited ability to intervene before potentially problematic transactions were completed.[1]
The case for reform had been building for years. A series of acquisitions in digital markets and concentrated industries had demonstrated the limits of a system in which the regulator could only act after the fact – by which time remedies were difficult to design and even harder to enforce. The Treasury’s 2023 review of the merger framework concluded that mandatory notification was necessary to bring Australia into line with the approach taken in virtually every other comparable jurisdiction, including the United States, the European Union, and the United Kingdom.
The new regime, which came into force on 1 January 2026, fundamentally changes the operating environment for anyone involved in Australian M&A. It is no longer a matter of assessing whether ACCC engagement is advisable – for transactions that meet the notification thresholds, it is mandatory, and completion without clearance carries significant penalties.[2]
What the First Three Months Have Revealed
The early data from the regime’s operation is instructive. Between 1 January and 31 March 2026, the ACCC received 50 merger notifications and 108 waiver applications – a total of 158 formal regulatory engagements in the regime’s first quarter alone. The ACCC approved 39 notifications through its phase 1 process and progressed two to the more intensive phase 2 review.[3]
Several observations are worth drawing from that data. First, the volume of waiver applications – more than double the number of formal notifications – reflects the fact that many parties are proactively seeking confirmation that their transaction falls below the notification thresholds before proceeding. This is prudent practice, but it also adds a step to the process that did not exist under the old regime. Second, the 80% phase 1 clearance rate within 15 to 20 business days is broadly consistent with the ACCC’s stated expectation, suggesting that straightforward transactions are moving through the process relatively efficiently.
What cannot yet be fully assessed is the tail risk on phase 2 reviews. With only two phase 2 decisions in the first quarter, the sample size is too small to draw conclusions about how long complex reviews will take or what remedies the ACCC will seek. That uncertainty will be a feature of the landscape until the regime has accumulated a more substantial body of practice.[4]
Who the New Rules Actually Capture – Including Mid-Market Deals
A common misconception among mid-market dealmakers is that the new regime primarily affects large transactions. The notification thresholds – which are based on a combination of deal value, the acquirer’s Australian turnover, and the target’s Australian turnover – are calibrated in a way that captures a significant proportion of mid-market M&A activity, not just major corporate transactions.[5]
A business with a meaningful Australian revenue base that is being acquired by a larger domestic or international player may well meet the turnover thresholds, even if the absolute deal value is modest by large-cap standards. Serial acquirers – companies that are building through multiple bolt-on acquisitions – need to be particularly attentive, as the aggregate effect of successive acquisitions may be assessed by the ACCC even if each individual transaction is close to the threshold margin.
For transactions in sectors where the ACCC has signalled particular interest – digital markets, data-intensive businesses, healthcare, professional services, and industries with meaningful vertical integration – the threshold question is only the starting point. Even transactions that would ordinarily receive phase 1 clearance may attract closer scrutiny if they involve players in markets the regulator is actively monitoring. Understanding where your proposed transaction sits in the ACCC’s current priority landscape is an important early step in any deal process.
The Practical Implications for Deal Timetables and Strategy
The most immediate operational consequence of the new regime is the need to build regulatory clearance time into transaction timetables from the outset. Under the old system, parties could sign a transaction and move toward completion on a timeline entirely of their own choosing. Under the new regime, completion is legally prohibited until ACCC clearance is obtained – and the ACCC has 15 to 30 business days for a phase 1 decision, with the possibility of extension if it requests further information.[6]
In practice, this means that a transaction signed in, say, March cannot be assumed to close in April. For transactions that require phase 2 review – where there is no fixed outer time limit – completion timelines become genuinely uncertain. Vendors who have structured their post-sale plans around a defined settlement date, or buyers who have financing facilities with defined drawdown windows, face real risks if the regulatory timeline extends beyond expectations.
The implications extend beyond timetabling. The quality of the initial merger notification submission matters significantly. A well-prepared submission that provides the ACCC with a comprehensive and well-organised set of information about the markets involved, the competitive dynamics, and the rationale for the transaction is more likely to receive an early phase 1 clearance than one that leaves the regulator with unanswered questions. Investing in a thorough submission from the outset – with experienced advisors who understand the ACCC’s analytical framework – is not just good practice; it is a meaningful driver of deal certainty.
What Dealmakers Should Be Doing Differently Now
The practical adjustments required by the new regime are real but manageable for parties who engage with them early. The fundamental shift is in when regulatory thinking enters the M&A process. Under the old system, ACCC considerations were often addressed late – once a transaction was substantially agreed and attention had turned to execution. That approach is no longer viable.
Preliminary competition analysis should now be conducted as part of the initial assessment of any potential acquisition target. Understanding how the combined entity would be positioned in relevant markets, whether the transaction might raise market concentration concerns, and which ACCC priority sectors the deal touches should inform both the decision to proceed and the structure of the transaction – well before any binding agreement is reached. In some situations, that early analysis may identify competition issues that can be addressed through structural remedies proactively offered to the ACCC, which can materially reduce review risk.
For businesses that are themselves potential acquisition targets – or that may pursue acquisitions as part of their own growth strategy – the new regime is also a prompt to review corporate documentation and market position analysis with a view to being ready for a merger notification process when the time comes. A data room that is well organised and that addresses the information requirements of a merger notification from the outset is a tangible competitive advantage in a world where deal certainty and timeline predictability matter.
Conclusion
Australia’s mandatory merger control regime represents a genuine and durable change to the operating environment for M&A, not a temporary procedural adjustment. The early months of the regime’s operation confirm that the ACCC is administering it actively and that the volume of transactions requiring formal engagement is substantial. For boards, management teams, and advisors involved in Australian M&A, the appropriate response is not to treat the new regime as a box to be ticked late in a process, but to integrate competition analysis and ACCC strategy into deal thinking from the very beginning. Those who do will transact with greater certainty and fewer surprises; those who do not will find themselves managing regulatory risk at the worst possible moment.
Footnotes:
[1] MinterEllison, “A new year, a new Australian merger control regime,” January 2026.
[2] Norton Rose Fulbright, “Australia’s new mandatory merger control regime,” January 2026.
[3] ACCC, “New merger control regime off to positive start,” Media Release, April 2026.
[4]Corrs Chambers Westgarth, “The new ACCC merger regime: a round-up of recent announcements,” February 2026.
[5] Carter Newell, “Mandatory merger notifications: what to know about the 2026 reforms,” 2026.
[6] White & Case, “Australia’s new mandatory merger control regime: Notification waivers,” 2026.
