Last-minute changes to Australian merger control ahead of 1 January 2026 start date

What you need to know

• Amendments to Australia's soon-to-commence merger regime have been registered on the Federal Register of Legislative Instruments.
• The amendments include several material changes to the thresholds in relation to the treatment of assets; new requirements to notify certain acquisitions even where they do not result in an acquisition of control; carve-outs for land acquisitions which are in the ordinary course of business; various financial market exceptions and more.
• The majority of the amendments will become effective on 1 January 2026, but the new transaction thresholds for certain asset acquisitions and the control carve-outs will only commence on 1 April 2026.

What you need to do

• Review the key elements of the regime, including updated thresholds and other important information on Ashurst's Australian Merger Reforms website.
• From 1 January 2026, notify the ACCC of mergers exceeding the various thresholds, or request a waiver if appropriate.

Last-minute changes ahead of 1 January 2026 start date

With just under two weeks until the new Australian merger regime commences, Treasury has registered an amending Determination that makes substantive changes to the regime. The amendments have been consulted on both publicly and privately, and include several of the "refinements" announced by Assistant Minister Andrew Leigh on 15 October 2025.

For an overview of the regime (incorporating these updates), visit Ashurst's Australian Merger Reforms website.

The "core" of the regime (including the vast majority of the changes made by the amending Determination) will take effect, as planned, on 1 January 2026. The start date for a handful of the new elements has been deferred until 1 April 2026.

Key changes made by the amending Determination include the following:

• Changes to how revenue is attributed to assets: The amending Determination repeals the 20% of market value fallback calculation for asset acquisitions. Instead, where the acquisition is of an asset and the acquisition has the effect that a person will, or can, acquire all or substantially all of the assets of a business, the amount to be calculated to determine whether the monetary threshold is met, is the Australian revenue of the target to the acquisition to the extent it is attributable to the business. Where an asset is not all or substantially all of the assets of a business, the transaction value threshold will apply.
• Additional changes to certain asset acquisitions from 1 April 2026: From 1 April 2026, additional transaction value thresholds will apply to asset acquisitions which are not of all or substantially all of the assets of a business. From 1 April 2026, those acquisitions will have to be notified where:
  • the Acquirer's Australian revenue is ≥$500 million and the global transaction value is $50 million; and
  • the combined Australian revenue of the Acquirer and Target is ≥$200 million and the global transaction value is $200 million.
• Exclusions from 3 year look-back calculation: The 3-year look back has been modified to exclude certain transactions, such as acquisitions of non-controlling interests in bodies corporate and acquisitions of shares or assets which have been subsequently divested.
• Requiring certain transactions to be notified regardless of whether control is acquired: From 1 April 2026, certain transactions must be notified even where they do not result in an acquisition of control (if they meet the thresholds). Some of these changes close potential notification gaps and others are intended to provide a bright line to ensure the ACCC is notified of acquisitions that may alter market dynamics. From 1 April the following acquisitions will have to be notified where they meet the thresholds:
  • in any non-Chapter 6 entity - increasing voting power from 20% or below to more than 20%;
  • in any body corporate - increasing voting power from a starting point of 20% to 50%, to an end point that is 50% or more;
  • in a Chapter 6 entity - increasing voting power from 20% or below to more than 20% (where you already had control); or
  • in a Chapter 6 entity - increasing voting power from below 20% to 50% or more (without control either before or after the acquisition).
• Shareholder protection rights do not equal "associates": Changes have been made which are intended to ensure that entities with minority shareholder protection rights are not to be considered "associates" merely because they hold those rights.
• Carving out acquisitions of land in the ordinary course of business: Acquisitions of land in the ordinary course of business will not require notification (though this will not apply to supermarkets). The "ordinary course of business" carve-out is intended to apply to routine acquisitions of a legal or equitable interest in land, whether freehold or leasehold. Examples include land for an office, headquarters or other routine trading activities. Importantly, this is not a blanket exception and there will be land and lease acquisitions which still require notification, as they fall outside the "ordinary course of business". It is also important to note that the "ordinary course of business" does not refer to the business of the acquirer in particular, but rather to business in general.
• Transitional arrangements for equitable land and leases entered into prior to 1 January 2026: Interests in land or quasi-land rights put into effect from 1 January 2026 are exempt from notification if they are subsequent to a previous acquisition of an interest in the same asset by the same acquirer prior to 1 January 2026. For example, lease agreements entered into after 1 January 2026, where the agreement for lease over the same property was entered into prior to 1 January 2026, will not need to be notified. The size of land, proportion of ownership and the acquirer must all be the same.
• Procedural elements of waivers: The amendments include the finalised waiver application form, as well as other procedural elements of waivers, such as the information to be included on the acquisitions register and the 25 Business Day decision timeframe (failing which, a waiver will be refused).
• Financial markets amendments: The amendments also make various changes to the exceptions which apply to a variety of financial market activities, ranging from external administration; close out and netting; derivatives; foreign exchange contracts; debt instruments, money lending and financial accommodation; and in superannuation contexts. These are all very technical and individual advice should be obtained before relying on them.

Ashurst's Australian Merger Reforms website provides a comprehensive overview of the new regime, and has been updated to reflect the latest round of amendments. You can view it here.

Want to know more?

• Ashurst Australian Merger Reforms hub