From 1 January 2026, Australia will transition to a mandatory and suspensory merger control regime. In a series of articles, we have tracked the progress of the reform package including the release of draft notification thresholds and the impact of the reforms passed by parliament. Australia has entered the final stretch, with the regime commencing on a transitional basis from 1 July 2025. In the final few months before the regime commences in full, businesses should be taking steps to ensure that the regime is properly considered in the context of deals that are currently being considered and / or negotiated. Careful planning and analysis will be needed as we enter the next phase of the reforms.

Transitional arrangements: Regime will commence in full in January 2026, but voluntary filings under new regime now possible

The new regime will apply to acquisitions that are 'put into effect' (i.e. that complete) from 1 January 2026, meaning the new regime will apply to many deals that are signed in H2 2025 which will or may complete on or after 1 January 2026 (even due to unexpected timing delays).
The following transitional arrangements apply:

From 1 July 2025 to 31 December 2025:

• Merger authorisation applications under the formal merger authorisation route (rarely used) are no longer possible.
• Informal clearance applications are permitted but should be submitted as early as possible to mitigate the risk of the review not being completed by 31 December 2025. The ACCC has indicated that anything submitted 'after early October… [is] much less likely to be considered in time', even where limited or no competition risks arise. Where informal clearance is granted during this period, the merger parties will then have 12 months to put the acquisition into effect (if that does not occur, then a notification under the new regime will be required). This provides a window in which potential risks under the new regime can be managed through filing under the current regime.
• Voluntary notification under the new formal regime is available.
• Where an informal pre-assessment was finalised under the current regime before 1 July 2025, but the acquisition may not be put into effect by 31 December 2025, parties will need to consider re-engaging with the ACCC to seek updated or 'refreshed' informal review. Parties are able to 'refresh' a prior clearance from 1 July 2025.

From 1 January 2026:

• From 1 January 2026, acquisitions of shares or assets that meet the notification thresholds will need to be notified to the ACCC, unless an exemption applies. Failure to notify a notifiable acquisition will result in the acquisition being void and expose the parties to substantial penalties.
• Where an acquisition that meets the notification thresholds has been notified to the ACCC under the current regime but the ACCC's review remains ongoing at 31 December 2025, this will result in a 'no decision' outcome. The acquisition will need to be (re)notified and assessed under the new regime. While the ACCC may adopt a truncated review to reflect work already done, the ACCC has not provided clarity about how this will work in practice.
• For acquisitions that do not meet the notification thresholds, there is no requirement to notify. However, the existing prohibition on anti-competitive acquisitions of shares or assets remains, so the ACCC retains the ability to investigate and take enforcement action. Acquisitions which are below threshold but may raise competition concerns may require voluntary filing under the new regime.

Acquisitions that are caught by regime

The regime is broad – it applies generally to the acquisition of shares and / or assets. An asset includes ‘any kind of property, a legal or equitable right that is not property’, and specifically includes real estate/property interests and IP interests. The regime also captures the acquisition of units in unit trusts and interests in managed investment funds.

The breadth of acquisitions potentially caught is significant, with complex ‘associate’ and ‘connected entity’ concepts embedded in ‘control’ and/or revenue tests, discussed further below. These key concepts will create issues and uncertainty in practice and are different to the approach taken in other jurisdictions.

Notification thresholds

The finalised notification thresholds involve three monetary thresholds, including one directed at so-called creeping acquisitions. Additional thresholds can be designated by the Minister for areas requiring additional scrutiny, with only the supermarkets sector being designated to date.
A summary of the notification thresholds is outlined in the diagram below.

These revenue tests will require the merger parties to consider Australian revenue of the acquirer, their 'connected entities', the target and the target's connected entities (being directly or indirectly acquired). For these purposes:

• Australian revenue comprises each relevant entity's gross revenue, determined in accordance with accounting standards, which are attributable to transactions or assets within Australia or transactions into Australia, for the preceding 12 month reporting period prior to the contract date.
• 'Connected entities' is a complex concept that comprises both 'related' entities and 'controlled entities'. The former reflects the definition of 'related' under Australia's competition laws (s 4A), which invokes various notions of holding companies and subsidiaries. The 'controlled entity' concept is wider, resting on 'control' within s50AA of Corporations Act (which involves the capacity to determine the outcome of decisions about the second entity’s financial or operating policies), either alone or together with one or more 'associates' (within the meaning of Chapter 6 of the Corporations Act), itself a very wide concept. 'Associates' will require consideration of parties within a corporate group, parties to any agreements for the purpose of controlling or influencing a third party, and parties that act (or propose to act) in concert in relation to a third party. The connected entity test applies, in the context of the acquirer, to capture revenue of any 'connected' entities upwards and downwards in the chain.

In practice, there will be considerable complexity and uncertainty associated with determining all connected entities of the acquirer and target for the purposes of accurately calculating revenue, given the width of the above concepts. In some cases, this may not be determinative as to whether an acquisition is notifiable but, for other acquisitions, it may be critical and a failure to capture all applicable revenues may lead to an incorrect assessment as to whether the acquisition is notifiable.

For assets, the regulations also prescribe that this is the Australian revenue of the target to the extent it is attributable to the asset. Where this is not reasonably practicable, the revenue amount is 20% of the market value of the asset.

Finally, for the cumulative threshold, in assessing whether the accumulated revenue test is met, certain acquisitions are not included – namely previous acquisition of shares or assets where the Australian revenue of the target (including each connected entity) was less than A$2 million, and acquisitions that were previously notified under the new regime.

Exemptions

A key exemption for the purposes of the new regime is that an acquisition does not need to be notified if the acquirer will not control the target immediately post-acquisition, or where it already controlled the target immediately prior to the acquisition. Control for this purpose refers to s50AA of the Corporations Act (as discussed above) as well as a modified concept of control, in which an acquirer jointly – with one or more associates – has the relevant capacity to determine the outcome of decisions about the second entity’s financial or operating policies. This is likely to create practical issues with determining 'control', for example in relation to joint venture or shareholder arrangements, for the purposes of this exemption.
There are a range of property related exemptions, including the acquisition of a legal or equitable interest in land for specific purposes, namely developing residential premises, or carrying on a business primarily of buying, selling, leasing or developing land. This turns on the purpose for which the land will be used. No exemption applies where the party will use the land to operate other commercial activities. Other land exceptions include some lease extensions or renewals, and interests relating solely to a sale and leaseback arrangement, among others.

There are also other technical exemptions, for example:

• for financial arrangements (e.g. acquisitions of shares or assets which are debt instruments, asset securitisation, etc), although there are certain carve outs to these exemptions – for example, in the context of an acquisition of an equity interest, where an acquisition that has the effect that a person will begin, or can begin, to ‘control’ the business, or in the context of an acquisition of an asset, where the acquisition has the effect that a person will, or can, acquire all, or substantially all, of the assets of a business.
• for acquisitions of shares giving 20% or less voting power in a Chapter 6 entity under the Corporations Act.

Filing fees finalised

The filing fees are significant and will likely have a chilling effect on some lower value deals. Fees range from A$8,300 for a notification waiver, A$56,800 for a standard filing, and an additional A$475,000 – A$1,595,000 for a complex Phase 2 review depending on the size of the acquisition (e.g. $475,000 if the transaction value is <A$50 million, or $855,000 for transactions between A$50 million and A$1 billion).

Filing forms finalised

The regulations include prescribed forms for:

• prenotification engagement with the ACCC
• a 'short form' filing
• a 'long form' filing
• a public benefits application.

In tandem, ACCC guidance has been released explaining expectations on the use of short vs long form notifications for a given acquisition. These forms require significant amounts of information and documents to be provided, even with a short form filing, although the requirements are (as expected) more extensive for long form filings.

Further guidance has been released

The ACCC is continuing to release further guidance including a final version of the merger assessment guidelines that we have outlined in Australia's mandatory merger control regime takes shape. Other key recent developments include the following:

• Competitive / contested bid scenarios: At present, the ACCC reviews applications in contested bid scenarios. Currently, bidders often 'go in early' to the ACCC to seek to gain comfort about potential regulatory risk to improve the attractiveness of their bid or to enable early engagement with the ACCC. This will no longer be available under the new regime. Subject to limited exceptions (e.g. hostile takeovers), the ACCC's view is that an acquisition will only be able to be notified where there are signed transaction documents or where both parties intend to sign. This rules out the possibility of multiple bidders approaching the ACCC, with engagement (effectively) only permitted for the preferred bidder.
• Other guidance includes how the ACCC will use compulsory notices, and how the ACCC will investigate 'under threshold' acquisitions, as well as details of the 'acquisition register'.

Section 50 remains

While focus will be on the various notification thresholds, the current prohibition against anti-competitive mergers will remain and apply to all 'below threshold' acquisitions. This will mean that consideration will need to continue for below-threshold transactions as to whether any substantive competition issue may arise or may attract ACCC investigatory interest. Parties will be able to voluntarily opt-in to the new regime for below-threshold acquisitions to manage ACCC enforcement risk.

Preparing for the incoming regime: Key takeaways

Parties should be preparing for the incoming regime, including to account for the following:

• While the current informal clearance regime will remain in place until 31 December 2025, the ACCC has set an October 2025 deadline for applications under the current regime. As we progress through H2 2025 there will be an increasing focus on strategic decisions regarding filing and pathways.
• The ACCC has noted that reviews that are ongoing at 31 December 2025 will result in 'no decision' and will need to be notified under the new regime. The ACCC's message is – leave plenty of time for a review to be finalised, or file (voluntarily) under the new regime.
• Merger parties who have already signed transactions will need to monitor for any changes in the expected completion date. If there is a risk that completion may be pushed out into 2026, further assessment will be required – e.g. having regard to the notification thresholds or potentially to seek a 'refreshed' ACCC decision.
• For transactions being negotiated at present, parties need to consider appropriate conditions precedent to account for the new regime, including optionality that may be required depending on the timing for completion. MinterEllison is managing increasingly complex conditions precedents which are designed to manage risk through the transitional period.
• Expect further updates in the coming weeks and months as the government and the ACCC continues to release further guidance and we gather initial insights about the first filings made under the incoming regime.

MinterEllison's merger control experts have been working closely with clients to understand the new regime and transitional arrangements, map their acquisition plans and their strategy for ACCC engagement. Get in touch if you have any questions about the incoming regime and what it may mean for your business or your clients.