- What’s happening: Australia is replacing its voluntary merger notification system with a mandatory, suspensory regime from January 2026. Transactions above set thresholds will require ACCC approval before completion, with all filings published on a new public register.
- Why it matters: This is the most significant overhaul of Australia’s competition framework in decades. It gives the ACCC earlier, stronger, and more transparent oversight of consolidation, addressing long-standing concerns about creeping acquisitions, market concentration, and enforcement blind spots.
- What’s next: Voluntary notification is already underway. From January 2026, qualifying deals cannot proceed without ACCC clearance, and penalties for non-compliance will be severe. Early waiver decisions, Phase 1 clearance rates, and sectoral enforcement patterns will set expectations for how the regime operates in practice.
Australia’s competition regulator is weeks away from wielding unprecedented merger control powers it spent more than two decades advocating for.
From January 1 2026, the Australian Competition and Consumer Commission will operate a mandatory, suspensory merger control regime – one that requires pre-approval for transactions above defined thresholds and renders unapproved deals void. The shift ends a voluntary notification system that left the ACCC reliant on court injunctions to block anti-competitive consolidation.
The regime is designed to address persistent concerns about market concentration, “creeping acquisitions” in which firms make multiple small purchases over time, and enforcement gaps that allowed potentially harmful mergers to proceed unexamined. With voluntary notification already underway since July and mandatory commencement approaching, the framework is reshaping how deals are structured, assessed, and timed across the Australian economy.
For regulators, the reform offers lessons in institutional design, resource allocation, and the balance between transparency and administrative burden.
How the system works
Three monetary thresholds trigger mandatory notification. Deals involving parties with combined Australian turnover of at least $200 million must be notified if the target generates at least $50 million in Australian revenue or if the global transaction value exceeds $250 million. A lower threshold applies to very large acquirers – those with $500 million or more in Australian turnover – acquiring targets with at least $10 million in Australian revenue.
The regime also captures “serial acquisitions” – purchases of businesses in the same or substitutable markets within a three-year window. These transactions are aggregated for threshold purposes, even if individual deals were not initially notifiable. The measure targets roll-up strategies common among private equity firms and digital platforms.
Once notified, deals enter a two-phase process. Phase 1 reviews take up to 30 business days, with fast-track approval possible after 15 days if no competition concerns arise. Most transactions are expected to clear at this stage. If issues emerge, the ACCC initiates a Phase 2 review lasting up to 90 business days, which may result in clearance with conditions or outright prohibition.
Penalties are substantial. Failure to notify a qualifying transaction, or completing it without ACCC approval, attracts the greater of $50 million, three times the benefit obtained, or 30% of adjusted turnover for corporations. The acquisition itself is rendered void.
All notified transactions appear on a public register, including party identities, transaction details, and the ACCC’s decision rationale. Third-party submissions remain confidential, but the register represents a significant departure from the confidential informal process that preceded it.
The transition period
Voluntary notification under the new regime began on July 1 2025, allowing early engagement before the mandatory system commenced. Deals granted informal clearance before July 1 that completed before year-end were exempt from the new requirements. Those extending into 2026 required an updated ACCC view by early October or re-filing under the new rules.
The ACCC advised that informal clearance applications received after October 1, 2025 were unlikely to be reviewed before December 31, 2025, when the informal clearance system definitively ended, effectively making early October the practical deadline for new applications.
The government has also designated the major supermarkets – Coles and Woolworths – for mandatory notification even for property acquisitions above certain size thresholds. Healthcare, fuel, and other consumer-facing sectors have been flagged for potential future designation, signalling the regime’s sectoral focus.
Why the reform happened
Australia’s voluntary regime had long been an outlier among OECD nations: until now, it was one of only three OECD countries – alongside Haiti and Israel – without a mandatory merger notification requirement. The ACCC could not block mergers without securing a court injunction – a high evidentiary bar that made post-completion court challenges extremely difficult, with the ACCC achieving limited success in contested merger litigation since the SLC test was reintroduced in 1993
The regulator argued this left harmful deals unexamined, particularly in sectors experiencing rapid consolidation. Market concentration in supermarkets, healthcare, banking, and digital platforms provided evidence that the voluntary system was no longer fit for purpose. With many transactions never notified at all, the Commission lacked visibility over potentially anti-competitive activity.
International alignment also drove the reform. The EU, US, and Canada have long operated mandatory filing regimes. Australia’s shift brings it into line with global best practices, including suspensory obligations, risk-based thresholds, and transparent decision-making.
The ACCC has advocated for these changes since at least 2017, with formal reform proposals presented in 2021. These produced multiple inquiry reports documenting enforcement gaps and market concentration trends. The government announced the reform in April 2024, with legislation passing Parliament in November 2024.
Competing perspectives
Business groups acknowledge the rationale for mandatory notification but warn of unintended consequences. During the consultation process, the Business Council of Australia criticized the initially proposed requirement for ‘substantial’ public benefits, arguing it would exclude socially beneficial mergers. The final legislation adopted a net public benefit test in response to these concerns, though procedural fairness concerns remain.
Extended timelines and filing fees represent substantial increases in the cost of doing deals in Australia. Fees range from $8,300 for a notification waiver to $56,800 for Phase 1 review, and between $475,000 and $1.595 million for Phase 2 assessments depending on transaction value. Australia has adopted a “full cost recovery” model, shifting the expense of merger review from taxpayers to merging parties.
Competition lawyers see improved process certainty but caution that the regime is highly prescriptive. Complex rules around “control,” revenue calculation, and exemptions require careful navigation. Serial acquisition aggregation and goodwill protection clauses such as non-competes are flagged as areas of particular complexity, especially for private equity.
The ACCC maintains that the reforms enable better protection of competition, innovation, and consumer welfare through earlier intervention and transparency. It has committed to meaningful pre-notification engagement, clear analytical guidance, and disciplined adherence to statutory timelines.
Economists, including scholars at the International Center for Law and Economics, have expressed reservations about structural presumptions based on market concentration, arguing these may not reliably predict competitive harm and could deter efficient consolidation.
What regulators are watching
The regime’s first year of operation will shape expectations for the decade ahead. Early patterns in waiver decisions, Phase 1 clearance rates, and sectoral enforcement will signal how the ACCC exercises its expanded powers. The public register – a transparency mechanism with few international equivalents at this scale – offers unprecedented visibility into merger activity and regulatory reasoning.
Resource demands are substantial. The ACCC must manage increased workload, statutory timelines, and public accountability while maintaining analytical rigour. Coordination with other regulators, including the Treasury, the Foreign Investment Review Board, and the Digital Platform Regulators Forum, will determine whether the regime complements or complicates Australia’s broader regulatory architecture.
For jurisdictions considering similar reforms, Australia’s experience offers a near real-time case study in institutional design, stakeholder management, and the practical challenges of implementing mandatory merger control in a mid-sized, open economy.
The regime’s ultimate test is whether it strikes the right balance between protecting competition and enabling efficient, pro-competitive mergers that drive innovation and economic growth. Early indicators suggest the system is working as designed, but the full picture will emerge only as enforcement patterns, tribunal reviews, and market responses become clear.
