Australian Merger Reforms FAQs

Our Australian Merger Reforms Hub helpfully sets out the general notification thresholds that apply from 1 January 2026.

In this case, the acquisition of 100% of the shares in an Australian company will be notifiable where:

(a)  if the acquirer's Australian revenue in the most recent financial year is $500 million or more:

(i) the Australian revenue of the target company in the most recent financial year is $10 million or more; or

(ii) the combined Australian revenue of the target company and the Australian revenue from previous acquisitions by the acquirer over the past

3 years involving goods or services that are the same, substitutable, or otherwise competitive with the target company is $10 million or more. 

(b)  if the combined Australian revenue of the acquirer and the target company in the most recent financial year is $200 million or more:

(i) the target company's Australian revenue in the most recent financial year is $50 million or more; or

(ii) the combined Australian revenue of the target company and the Australian revenue from previous acquisitions by the acquirer over the past 3 years involving goods or services that are the same, substitutable, or otherwise competitive with the target company is $50 million or more. This is referred to as the "serial acquisition" test, which is discussed in more detail in Question 5; or

(iii) the global transaction value is $250 million or more.

However, if the target company's Australian revenue in the most recent financial year is less than $2 million, the acquisition does not require notification under the "serial acquisition" test based on the "de minimis exception".

In calculating the Australian revenue of the acquirer, you need to take into account the revenue of the acquiring entity that is party to the transaction together with all of its "connected entities". "Connected entities" include other entities in the acquiring corporate group that:

• the acquiring entity controls (subsidiaries);
• control the acquiring entity (parents); or
• that are controlled, with the acquiring entity, by a common entity (sister entities).

In calculating the Australian revenue of the target, you need to take into account the revenue of the entity who is party to the transaction, together with all of its connected entities (as described above) that will be directly or indirectly acquired through the transaction.

There are a number of important exceptions to the requirement to notify the ACCC. These include share acquisitions that do not result in the acquisition of control over the target entity (until 1 April 2026, when dditional obligations to notify certain non-controlling interest come into effect, as described further in Question 3); internal restructures and reorganisations; certain ordinary course of business transactions (other than acquisitions of patents) (discussed further in Question 18); certain acquisitions of shares in Chapter 6 entities; various financial instruments such as debt instruments (including contingent debt), loans, debt interests in an entity, and securities financing transactions (discussed further in Question 4) and more.

The thresholds above are set out on the basis that no relevant exception to notification would apply to a transaction. Parties should seek legal advice before relying upon any of the exceptions to notification as they are highly technical.

Our Australian Merger Reforms Hub helpfully sets out the general notification thresholds that apply from 1 January 2026.

When considering an acquisition of less than all of the shares in a company, it is first necessary to determine whether the size of the interest gives rise to a notifiable acquisition.

• Until 31 March 2026, the share acquisition will only be notifiable if it results in the acquirer obtaining control over the target company. The concept of "control" turns on whether a party (either alone or with its associates) has the capacity to determine the outcome of decisions about an entity’s financial and operating policies (i.e. typically its budget and business plan). The focus is on the "practical" influence a party has and patterns of behaviour (rather than solely on the rights it can formally enforce).
  The Ministerial Determination does clarify, however, that an entity will not be taken to be an associate in relation to another entity simply because the first entity has a relevant agreement with the second entity that confers the first entity with standard minority shareholder protection rights.

• Changes to the minority interest rules come into effect from 1 April 2026. From that date, ACCC notification will also be triggered where an acquisition of shares results in the voting power of the acquirer (including its associates) in a body corporate increasing from 20% (or below) to above 20%, or from a point that is between 20% or more but 50% or less, to above 50%. This applies regardless of whether 'control' in the sense described above exists.

Put another way, from 1 April 2026 an acquisition that will result in voting rights of 20% or less will only be notifiable if it involves an acquisition of control, but an acquisition that will result in voting rights above 20% will be notifiable without any need for vetoes or other control rights (assuming that the monetary notification thresholds are also met).

In this case, if the acquisition of the 40% interest comes with veto rights over business plans, budgets and/or the strategic direction of the company, then the acquisition is likely to fall within the merger regime both now and also after 1 April 2026.

It is then necessary to determine whether the monetary filing thresholds are met. In this case, the acquisition will be notifiable where:

(a)  if the acquirer's Australian revenue in the most recent financial year is $500 million or more:

(i) the Australian revenue of the target company in the most recent financial year is $10 million or more; or

(ii) the combined Australian revenue of the target company and the Australian revenue from previous acquisitions by the acquirer over the past 3 years involving goods or services that are the same, substitutable, or otherwise competitive with the target company is $10 million or more. This is referred to as the "serial acquisition" test, which is discussed in more detail in Question 5; or

(b)  if the combined Australian revenue of the acquirer and the target company in the most recent financial year is $200 million or more:

(i) the target company's Australian revenue in the most recent financial year is $50 million or more; or

(ii) the combined Australian revenue of the target company and the Australian revenue from previous acquisitions by the acquirer over the past 3 years involving goods or services that are the same, substitutable, or otherwise competitive with the target company is $50 million or more. This is referred to as the "serial acquisition" test, which is discussed in more detail in Question 5; or

(iii) the global transaction value is $250 million or more.

However, if the target company's Australian revenue in the most recent financial year is less than $2 million, the acquisition does not require notification under the "serial acquisition" test based on the "de minimis exception".

There are a number of important exceptions to the requirement to notify the ACCC. These include share acquisitions that do not result in the acquisition of control over the target entity (until 1 April 2026, when additional obligations to notify certain non-controlling interests come into effect, as described further in Question 3; internal restructures and reorganisations; certain ordinary course of business transactions (other than acquisitions of patents) (discussed further in Question 18); certain acquisitions of shares in Chapter 6 entities; various financial instruments and more.

The thresholds above are set out on the basis that no relevant exception to notification would apply to a transaction. Parties should seek legal advice before relying upon any of the exceptions to notification as they are highly technical.

Yes, it might.

The acquisition of units in a unit trust is assessed as if the trust is a body corporate and the units are shares in the capital of that body corporate. If an acquisition of units in a unit trust otherwise meets the monetary thresholds and no relevant exception applies, then the acquisition must be notified to the ACCC.

It is also possible that the acquisition in relation to securities, there are a number of specific financial market exceptions that might apply. For example, acquisitions of debt instruments (including contingent debt), loans, debt interests in an entity, and securities financing transactions, will not be notifiable where the acquisition does not result in control of an entity that a person did not control before the acquisition. Further, asset securitisation arrangements and the taking or acquiring of a security interest do not have to be notified.

However, this exception does not extend to enforcing a security interest. If you are enforcing a security interest (e.g. a distressed business sale) then that acquisition would need to be notified where the applicable thresholds are met.

Further, if security is taken as part of a broader transaction and the monetary thresholds are otherwise met, you should consider the transaction as a whole because the exception may not be applicable in all circumstances.

Yes. Depending on the scale and frequency of your small, standalone acquisitions, you might be caught by the "serial acquisition" test. This test is also sometimes called the "3 year lookback".

If, within a 3 year period:

• you make multiple acquisitions of shares or assets that predominantly involve the supply or acquisition of the same goods or services, or goods or services that are substitutable for or otherwise competitive with each other; and

• collectively, the revenue associated with all of the shares and assets exceeds the notification threshold for a single acquisition (set out below), 

you must notify the acquisition that cumulatively exceeds the relevant threshold (Trigger Acquisition).

For acquirers with Australian revenue in the most recent financial year of $500 million or more, the cumulative threshold is only $10 million.

You will now also have to notify every subsequent acquisition of a business with revenue in the most recent financial year that exceeds $2 million after the Trigger Acquisition, until such time the cumulative threshold is no longer met based on the previous 3 year period.

In some cases it may be complex to determine when two businesses predominantly involve the supply or acquisition of the same good or services, or goods and services that are substitutable for, or otherwise competitive with, each other. Given the risk that a non-notified transaction is void, be careful when excluding acquisitions for your lookback on this basis.

If you have less than $500 million in revenue in the most recent financial year, a cumulative threshold of $50 million will apply to a transaction where the combined Australian revenue of the acquirer and the target in the most recent financial year is $200 million or more.

Identifying the acquisitions that must be counted towards the serial acquisition threshold can be tricky. You can exclude from the calculation of the cumulative thresholds:

(a)  any share acquisitions where the revenue of the target and its connected entities in the most recent financial year is less than $2 million;

(b)  any asset acquisitions that involve all or substantially all of the assets of a business (see the discussion in Question 17) where the revenue of that business in the most recent financial year is less than $2 million;

(c)  any asset acquisitions that did not involve all or substantially all of the assets of a business, where the market value of, or consideration payable for, the assets is less than $2 million;

(d)  any share and asset acquisitions that have separately been notified to the ACCC, except as a result of the 3-year lookback. Note that acquisitions for which waivers have been received are included in the threshold;

(e)  any transactions that are outside of the rolling 3 year time window. For example, if you sign a contract for an acquisition on 31 March 2026 you count all acquisitions since 1 April 2023; if the contract is signed on 30 April 2026 you count all acquisitions since 1 May 2023. An acquisition on 15 April 2023 counts for the first 3 year lookback calculation, but not for the second calculation;

(f)  any acquisitions of shares where neither the acquirer nor its connected entities still have control of the Target;

(g)  any acquisitions of assets that are no longer held by the acquirer or its connected entities; and

(h)  any acquisitions that are not connected with Australia.

It is important to make sure that you only count necessary acquisitions towards the serial acquisition threshold so that you do not notify the ACCC of a transaction unnecessarily.

See Question 2 for more information on what is a "connected entity".

The monetary thresholds require you to add together the relevant components of your transaction to determine whether a filing is required.
For example, if you:

(a)  acquire shares in a company with $5 million Australian revenue in the most recent financial year (ie revenue attributable to the target); and

(b)  acquire shares in another company in the group (a) and that company has $4 million Australian revenue in the most recent financial year (ie revenue attributable to connected entities of the target); and

(c)  acquire assets that represent all or substantially all of the assets of a business from the vendor as part of the same acquisition, and the revenue attributable to those assets from the most recent financial year is $3 million (ie revenue attributable to assets),

the relevant revenue for the purpose of monetary thresholders is $12 million (ie the sum of (a), (b) and (c)). If your business had $500 million or more in Australian revenue for the previous financial year, this acquisition would have to be notified to the ACCC.

The waiver process is available for straightforward transactions capable of being assessed based on the information provided with the application (i.e. 'on the papers'). The process has only been available since 1 January 2026 so we are still learning what transactions the ACCC is likely to be comfortable granting a waiver for – as more examples are published on the ACCC's Acquisitions Register, the likelihood of obtaining a waiver for a given transaction should become easier to predict.

As a general matter, however, a waiver may be suitable for a transaction where the following criteria are met:

(a)  there is no or limited overlap between the parties' operations, the definition of the "market" in which they operate is clear (or a decision can be made without reaching a view on the exact market definition) and the degree of concentration in the market is low (e.g. less than 5%) across the narrowest plausible markets;

(b)  there are no vertical overlaps between the parties or "conglomerate issues" (ie, a combination involving complementary or adjacent businesses) or - where there are such considerations - both the degree of concentration and the market shares of each of the merger parties in the relevant markets are low (e.g. less than 5%);

(c)  there are no complex scenarios or legal issues such as:

(i)  potential loss of future competition (e.g. where the target is a potential new entrant or nascent competitor);

(ii)  market concentration is already significant or high;

(iii)  the target is a vigorous and effective competitor;

(iv)  a failing firm scenario; or

(v)  complicated market definitions or the merger parties operate across multiple segments of a market/industry;

(d)  there is unlikely to be a risk of harm to consumers as a result of the acquisition; and

(e)  there are no issues that are likely to warrant consultation by the ACCC and/or inquiries with third parties.

The ACCC has a maximum of 25 business days to make a decision from the date it accepts a waiver application (in practice, the ACCC has been sending an email acknowledging acceptance of waiver applications once the waiver is filed and the relevant fee is paid), although the ACCC has said that it intends to provide waivers more quickly than this where possible. If a waiver is not granted within 25 business days it is deemed to be not granted and the parties must apply for notification.

An acquisition can only be formally notified to the ACCC if it has already been entered into (subject to ACCC clearance) or where all the proposed parties intend to enter into it. This means that in most cases the parties will have already signed transaction documents (containing a CP for ACCC clearance) prior to notification, including because the fact of the transaction will become public when the ACCC undertakes its "Phase 1" review and publishes the transaction on its Acquisitions Register.

It is, however, possible to commence ACCC notification based on a heads of agreement or memorandum of understanding for an acquisition provided that the document demonstrates sufficiently the necessary intention of the parties to enter into the transaction. Practically, to be accepted by the ACCC for notification, a heads of agreement will need to be sufficiently clear on all key commercial terms and be binding on the parties, reflecting the necessary intention of the parties to enter a formal agreement.

It is also possible to commence a confidential pre-notification consultation with the ACCC while the parties are still negotiating the transaction. This will help to expedite the clearance process once the transaction has been signed, because the parties will already have engaged with the ACCC on the notification form and any preliminary questions the case team may have. It will also help give the parties a sense of the ACCC's overall attitude towards the transaction and the likely clearance timeline following signing.

No. In this case, you will be acquiring shares in the joint venture entity, so the target company is that entity. The filing thresholds and "control" tests described in Question 3 above will apply to this transaction.

When applying these thresholds, the Australian revenue of the target's 'connected' entities will need to be included in its revenue, but only if the connected entities are being indirectly acquired through the acquisition. See Question 2 for more information on what is a "connected entity".
In this case, although the controlling parents of the joint venture entity would be 'connected' entities to the target, their turnover would not be counted as part of the revenue calculation for the joint venture entity because the parents are not being acquired as part of the transaction.

On the other hand, the revenue of any subsidiary entities controlled by the target joint venture entity should be included in the calculation.

Note, however, the nature, size and turnover of the joint venture partners might still be a relevant consideration when deciding whether you will apply for a waiver or otherwise consult with the ACCC.

The acquisition of vacant, freehold land located in Australia will be notifiable if it meets particular thresholds for asset acquisitions (unless an exception applies). The acquisition of a "quasi-land right" is also notifiable using the same thresholds – this will include a mining, quarrying or prospecting right, a water entitlement, or a right in relation to land for forestry operations.

For further discussion on the acquisition of non-vacant land, see Question 17.

Until 31 March 2026 the acquisition will be notifiable if:

(a)  the acquirer's Australian revenue in the most recent financial year is $200 million or more; and

(b)  the market value of, or consideration payable for, the land and any other assets being acquired is $250 million or more.

From 1 April 2026 the acquisition will be notifiable if:

(c)  the acquirer's Australian revenue in the most recent financial year is $200 million or more; and

(d)  the market value of, or consideration payable for, the land being acquired is $200 million or more,

or:

(e)  the acquirer's Australian revenue in the most recent financial year is $500 million or more; and

(f)  the market value of, or consideration payable for, the land being acquired is $50 million or more.

Certain exceptions from the obligation to file may be available if:

• the acquisition of the land is in the ordinary course of business – for more details about when you can rely on this, see Question 18;

• the land is being acquired to develop residential premises;

• you are acquiring the land for the purpose of carrying on a business primarily engaged in buying, selling, leasing or developing land (but not for operating a commercial business on the land);

• the acquisition of the land relates only to a sale and leaseback arrangement relating to the land; or
  an equitable interest in the relevant land has already been acquired by the acquirer prior to 1 January 2026 (discussed further in Question 19 below).

If you think that one of these exceptions may apply, detailed consideration should be given to the facts and the exception because the relevant provisions are technical and getting it wrong means the transaction is void as if it never happened. Voiding could present particular issues in relation to property transactions, for example in relation to the registration of property interests.

A lease of vacant land in Australia is treated as an acquisition of assets under the new regime, and the lease will be notifiable if it meets the asset acquisition thresholds set out in Question 15. Until 31 March 2026 the acquisition will be notifiable if:

(a)  the acquirer's Australian revenue in the most recent financial year is $200 million or more; and

(b)  the market value of, or consideration payable for, the land and any other assets being acquired is $250 million or more.

From 1 April 2026 the acquisition will be notifiable if:

(c)  the acquirer's Australian revenue in the most recent financial year is $500 million or more; and

(d)  the market value of, or consideration payable for, the land being acquired is $50 million or more.

or

(e)  the acquirer's Australian revenue in the most recent financial year is $200 million or more; and

(f)  the market value of, or consideration payable for, the land being acquired is $200 million or more.

For the purpose of calculating the filing thresholds in relation to a lease, the market value of, or consideration payable for, the lease is the value of all payments anticipated to be made to the landlord under the lease (which might be broader than only the rental payment amounts). Some care needs to be taken when considering the treatment of options, indexing and ancillary payments such as incentives.

Certain exceptions from the obligation to file may be available if:

• the entry into the lease is in the ordinary course of business – for more details about when you can rely on this, see Question 18;

• the land is being leased to develop residential premises;

• you are leasing the land for the purpose of carrying on a business primarily engaged in buying, selling, leasing or developing land (but not for operating a commercial business on the land);

• the transaction is a sale and leaseback arrangement relating to the land; or

• the relevant lease involves an extension or renewal of an existing lease.

If you think that one of these exceptions may apply, detailed consideration should be given to the facts and the exception because the relevant provisions are technical and getting it wrong means the transaction is void as if it never happened.

The lease of the land and facilities in Australia will be notifiable if it meets particular thresholds for asset acquisitions (unless an exception applies).

The applicable thresholds vary depending on whether or not you are acquiring all or substantially all of the assets of a business. The concept of "all or substantially all of the assets of a business" is not defined. The explanatory materials to the Ministerial Determination provide that this is a question of fact, considering whether the acquisition:

(a)  is of discrete assets, suggesting it is not all or substantially all of the assets of a business; or

(b)  alternatively, would enable the acquirer to effectively continue operating a business that is similar to the business currently operated using the acquired assets, suggesting that the transaction does involve all or substantially all of the assets of a business.

The test does not require the acquisition to be of all of the assets of the vendor's overall business.

The lease of the land and facilities in Australia will be notifiable if it meets particular thresholds for asset acquisitions (unless an exception applies).

The applicable thresholds vary depending on whether or not you are acquiring all or substantially all of the assets of a business. The concept of "all or substantially all of the assets of a business" is not defined. The explanatory materials to the Ministerial Determination provide that this is a question of fact, considering whether the acquisition:

(a)  is of discrete assets, suggesting it is not all or substantially all of the assets of a business; or

(b)  alternatively, would enable the acquirer to effectively continue operating a business that is similar to the business currently operated using the acquired assets, suggesting that the transaction does involve all or substantially all of the assets of a business.

The test does not require the acquisition to be of all of the assets of the vendor's overall business.

In this case, if you are able to use the manufacturing facility and the warehouse to operate a business without significant further input, you are likely to be acquiring all or substantially all of a business. The acquisition will require notification to the ACCC where:

(a) if the acquirer's Australian revenue in the most recent financial year is $500 million or more:

(i) the Australian revenue of the manufacturing business in the most recent financial year is $10 million or more; or

(ii) the combined revenue of the manufacturing business and the Australian revenue from previous acquisitions by the acquirer over the past 3 years involving goods or services that are the same, substitutable, or otherwise competitive with the business division is $10 million or more. This is referred to as the "serial acquisition" test, discussed in more detail in Question 5; or

(b) if the combined Australian revenue of the acquirer and the manufacturing business in the most recent financial year is $200 million or more:

(i) the business division's Australian revenue in the most recent financial year is $50 million or more; or

(ii) the Australia revenue of the business division and the Australian revenue from previous acquisitions by the acquirer over the past 3 years involving goods or services that are the same, substitutable, or otherwise competitive with the business division, is $50 million or more ( This is referred to as the "serial acquisitions test"); discussed in more detail in Question 5; or

(iii) the sum of the market values of all assets being acquired or the consideration received or receivable for the assets being acquired is $250 million or more. It is important to note that the $250 million does not have to be the value of the Australian assets, meaning that this threshold can easily capture global transactions where a significant Australian acquirer (ie Australian revenue over $200 million) acquires a global target with very limited Australian operations or assets.

However, if the target business's Australian revenue in the most recent financial year is less than $2 million, the acquisition does not require notification under the serial acquisitions test based on the "de minimis exception".

If the facilities do not constitute all or substantially all of a business (for example, if they need to be integrated into your business and you need to obtain staff or other inputs in order to make the facilities market-facing) then the acquisition will require notification to the ACCC in the following circumstances:

Until 31 March 2026 the acquisition will be notifiable if:

(a) the acquirer's Australian revenue in the most recent financial year is $200 million or more; and

(b) the market value of, or consideration payable for, the assets being acquired is $250 million or more.

From 1 April 2026 the acquisition will be notifiable if:

(a) the acquirer's Australian revenue in the most recent financial year is $500 million or more; and

(b) the market value of, or consideration payable for, the assets being acquired is $50 million or more,

or

(c) the acquirer's Australian revenue in the most recent financial year is $200 million or more; and

(d) the market value of, or consideration payable for, the assets being acquired is $200 million or more.

Even if the relevant thresholds are met, it may be possible to conclude that the acquisition is exempt from notification on the basis that it is in the ordinary course of business (provided the facility is not currently owned by a competitor to the acquirer). This exception is discussed further in response to Question 18.

Where an acquisition of an interest in land or other assets is in the "ordinary course of business", it does not need to be notified to the ACCC, even if the filing thresholds are otherwise met.

There is limited guidance from the Government or the ACCC on when an acquisition of land, or an interest in land, is in the ordinary course of business and is therefore excluded from the merger regime. The answer may vary between different industries because the starting point is to identify whether the particular type of transaction is undertaken routinely by businesses in a similar industry setting (although not necessarily by the acquirer itself) and 'naturally passes without examination'.

Since the focus is on whether a transaction is in the ordinary course of business of companies generally, rather than the ordinary course of business of the acquirer specifically, even large or infrequent transactions can qualify as being in the ordinary course.

The explanatory materials accompanying the Mergers Determination identify the following examples of land acquisitions as likely to be in the ordinary course of business:

• an acquisition of an interest in land for the purpose of an office, headquarters or routine trading activities (in particular, signing a lease for new office space in a building);

• a retailer acquiring land for a warehouse;

• a manufacturer acquiring land for a new manufacturing facility;

• an energy generator acquiring land for a solar farm; and

• an energy distributor acquiring land to build pylons on.

On the other hand, the explanatory materials also identify certain examples of transactions that will not qualify as ordinary course, being:

• an acquisition that may have an anti-competitive purpose;

• an acquisition from a competitor or potential competitor, including acquiring land that a competitor is currently using, or transferring production capacity (eg manufacturing facilities) from one competitor to another; and

• land-banking.

While the ordinary course of business exception appears to provide a basis to exclude many routine property transactions from a merger filing obligation, if a transaction is incorrectly classified as ordinary course when it should have been notified, the effect of the law is currently that the transaction will be void as if it never happened.

Given this risk, until further examples and guidance are provided by the ACCC – or the potential changes to the automatic voiding provisions are passed by Parliament (see Question 1), some businesses may still choose to seek a waiver from notification from the ACCC for transactions that do not clearly fall within the examples set out above. Please see Question 7 for more information about waiver applications.

No. If you acquired an equitable interest in land before 1 January 2026 (for example, through entering into an AFL or option to purchase) and you will acquire the legal interest after 1 January 2026 (for example, by entering the lease or purchasing the land), the acquisition of the legal interest does not need to be notified to the ACCC unless:

(a)  the size of the land interest ultimately acquired is materially different to the size of the equitable interest; or

(b)  the identity of the acquirer(s) or their proposed interest in the land has changed since the equitable interest was acquired (for example, a different entity is acquiring the legal interest or the proportional ownership shares have changed).

Probably not. A lease renewal (and also a lease extension) will generally not be notifiable under the new regime because there is a specific exception for them.

However, a lease extension or renewal may still be notifiable if there is no continuous occupation of the same land by the same parties to the lease e.g. there is an additional tenant added to the lease, or the proposed lease extension or renewal is for a materially different parcel of land. In this case, it will be necessary to determine whether another exception is available, particularly the "ordinary course of business" exception discussed in Question 18.

No. There is an exception from the obligation to file under the regime where a security interest is taken or acquired or where an acquisition is directly related to taking that security interest.

However, this exception does not extend to enforcing a security interest. If you are enforcing a security interest (e.g. a distressed business sale) then that acquisition would need to be notified where the applicable thresholds are met.

Yes. Even if you are a Government business or department, or you are dealing with a Government business or department, if you make an acquisition that meets the filing thresholds and is not otherwise subject to the exceptions discussed in this guide, the transaction is likely to be notifiable.

An acquisition is void "as if it never occurred" if it has been put into effect and:

(a)  it was required to be notified to the ACCC but was not notified; or

(b)  it was notified to the ACCC and was not "finally considered". A notified acquisition is only "finally considered" once the ACCC or the Competition Tribunal has made a determination that the acquisition can or cannot be put into effect and all relevant appeal periods have elapsed; or

(c)  it was notified to the ACCC, was finally considered and the ACCC (or the Competition Tribunal) determined that it could be put into effect, but that determination has become "stale". A determination becomes "stale" if the acquisition has not been put into effect 12 months after the date of the determination.

For most acquisitions, it is irrelevant when the agreement was originally entered into: if the acquisition meets the thresholds and is put into effect after 1 January 2026, the merger regime applies and the acquisition is void if it is not notified to the ACCC.

The exception to this position is an acquisition of a legal interest in land where the acquisition of the previous equitable interest occurred before 1 January 2026 (for more information, see Question 19).

Voiding may also present serious risks for ancillary parties in transactions, for example lenders who may require further evidence of ACCC approval to ensure their interests are protected.

The ACCC may determine that an acquisition must not be put into effect if the ACCC is satisfied that the acquisition would, in all the circumstances, have the effect or be likely to have the effect, of substantially lessening competition in any market in Australia.

The ACCC will consider similar factors to those addressed under the previous, informal clearance process, including whether the acquisition:

(a)  removes a close or significant competitor;

(b)  occurs in a concentrated market;

(c)  restricts competitors' access to key inputs or customers;

(d)  results in vertical integration across the supply chain, or leverages market power into new markets; or

(e)  is part of a series of similar acquisitions that collectively impact competition.

Under the new regime, the ACCC may also determine that an acquisition will substantially lessen competition in a market if the acquisition would, in all the circumstances, have the effect, or be likely to have the effect, of creating, strengthening or entrenching a substantial degree of power in the market. While the ACCC has stated that it considers this language simply clarifies the test that already applied under the old regime, rather than introducing a substantive change to the test, it will nonetheless be important to bear this wording in mind when contemplating a transaction by a company that already has a meaningful market position.

The ACCC's determination must be made in writing, and it will publish written determinations for each waiver application or notification on its Acquisitions Register. In practice, if the ACCC is likely to block an acquisition the parties will have significant advance warning, including because the ACCC is not able to block an acquisition prior to completing a detailed Phase 2 merger review process.

The ACCC will generally not consider notifications from competing bidders, because the vendor will not yet have expressed an intention to enter into a transaction with a conscious bidder (which the ACCC requires in order to have jurisdiction to formally review an acquisition).

A formal notification can only be made once the parties have entered into the relevant agreement (subject to ACCC clearance) or can show that they intend to enter into the agreement (which may be evidenced through a heads of agreement or similar document – please see Question 8). The existence of an ongoing competitive bidding process will mean the parties cannot satisfy those requirements and the ACCC will not accept a notification until a final bidder has been selected and the agreement is in near final form.

There are some limited exceptions to this rule, for example surprise hostile takeover bids.

Importantly, however, competing bidders can still commence confidential pre-notification engagement with the ACCC (if the vendor agrees). This is most likely to happen in the later stages of a competitive sale process, and vendors should be conscious of the responses being provided by bidders to the ACCC to ensure that some consistency is achieved in relation to market and acquisition descriptions.

No, as long as the minor changes to the transaction structure have not substantively changed the basis on which the ACCC completed its competition analysis. In that case, your section 189 letter will remain effective and you have 12 months to complete the transaction from date of your section 189 letter before the clearance goes "stale".

However, if there are substantive changes to what the ACCC considered before issuing the section 189 letter you should consider whether it is necessary to renotify under the new regime. Changes that introduce a new owner, result in a difference in who controls the target post-acquisition, or impact the shares or assets being acquired might be reason to re-notify.