From 1 January 2026, Australia’s merger control system enters a new phase. The informal, voluntary approach that has shaped merger regulation for decades will be replaced by a mandatory and suspensory notification regime administered by the Australian Competition and Consumer Commission (ACCC).
For dealmakers, boards and advisers, this structural change shifts merger control from a risk managed in the background to a formal approval process that must be addressed early and deliberately.
The revised approach
Under the existing framework, parties were not legally required to notify the ACCC of a merger or acquisition. Many transactions were reviewed voluntarily, but completion was ultimately a commercial decision, with the risk of post-completion enforcement if competition concerns arose.
From 2026, that position changes. Where a transaction meets the notification thresholds, it cannot be completed unless and until clearance is granted, or the ACCC issues a waiver. The burden moves from the regulator stopping problematic deals to parties demonstrating, in advance, that their transaction should proceed.
Deals caught by the regime
The new regime applies broadly to acquisitions of shares, assets and other interests that have a sufficient connection to Australia. Whether notification is required turns primarily on monetary thresholds, rather than market definition alone.
Below is an overview of the key notification thresholds:
| Threshold category | When notification is required |
| General merger threshold | The combined Australian turnover of the acquirer group and target group is at least A$200 million, and either: (a) the target group has Australian turnover of at least A$50 million, or (b) the global transaction value is at least A$250 million. |
| Large acquirer threshold | The acquirer group has Australian turnover of at least A$500 million, and the target group has Australian turnover of at least A$10 million. |
| Serial or creeping acquisitions (standard) | Over a rolling three-year period, the cumulative Australian turnover of businesses acquired in the same or closely related markets reaches at least A$50 million. |
| Serial or creeping acquisitions (very large acquirers) | For acquirers with Australian turnover of at least A$500 million, the cumulative threshold over three years is reduced to A$10 million. |
| Small target exclusion | Acquisitions of businesses with Australian turnover below A$2 million are generally excluded from the cumulative acquisition test. |
| Supermarket acquisitions | Separate and more stringent notification requirements apply to certain acquisitions by major supermarket chains, reflecting sector-specific concentration concerns. |
A suspensory clearance regime
A defining feature of the new framework is that it is suspensory. That is, if notification is required, completion must wait.
Once notified, the ACCC will review the transaction through a structured process. Transactions that do not raise competition issues are expected to clear relatively quickly. More complex or concentrated transactions may be subject to deeper review, including market inquiries and economic analysis.
Unlike the old system, the ACCC’s decision effectively determines whether a transaction proceeds. While judicial review remains available, the practical contest will usually be resolved at the regulatory stage rather than in court.
Waivers and early engagement
To avoid unnecessary burden on low-risk transactions, the regime allows parties to apply for a notification waiver. This is intended for transactions that technically meet a threshold but plainly do not raise competition concerns.
In practice, waivers will reward early preparation. Parties who identify merger control risk late, or who provide incomplete information, may find themselves pushed into full notification even where competition issues are minimal.
The risk of non-compliance
The new regime carries real enforcement consequences. Completing a notifiable transaction without clearance or a waiver can expose parties to civil penalties, court orders undoing the transaction, and reputational damage.
For directors and officers, merger control compliance will become a governance issue, not simply a legal technicality.
Implications for deal planning
From 2026, merger control will need to be addressed at the start of a transaction, not near the end. Term sheets, exclusivity arrangements and transaction documents will need to account for notification risk, review timing and regulatory conditions.
Transactions that once closed quickly, particularly bolt-on acquisitions and minority investments, may now require formal regulatory engagement. The discipline of early competition analysis will be critical.
For deal planning purposes, conservative timetables should assume:
- 30-60 days for straightforward transactions with early engagement
- 60-90 days for more complex or concentrated transactions
- Longer than 90 days where remedies, divestments or contested issues are involved
2026 and beyond
Australia’s move to a mandatory merger regime aligns it more closely with overseas models, but it also introduces new complexity for domestic transactions that previously proceeded without regulatory friction.
Much will depend on how the ACCC administers the system in practice, particularly its approach to waivers, timing and low-risk deals. What is clear is that from 1 January 2026, merger control in Australia will no longer be optional, informal or easily deferred.
For anyone involved in mergers and acquisitions, it is now a core part of transaction strategy.