What Australia's 2026 Merger Law Reforms Mean for M&A and Corporate Finance Transactions, Practical Guide for Acquirers & Targets

Australia’s merger laws have undergone their most significant overhaul in decades. The Treasury Laws Amendment (Mergers and Acquisitions Reform) Act 2024 introduced a mandatory, suspensory merger notification regime that commenced on 1 January 2026, replacing the previous voluntary informal-clearance system that had governed merger control in Australia for more than forty years. Additional rule changes, including tightened exemptions and procedural refinements, took effect from 1 April 2026, further reshaping the regulatory landscape for deal teams. ASIC’s Corporate Finance Update Issue 28, published 28 April 2026, confirmed that these reforms are already driving material changes in the way corporate finance transactions are structured, timed and documented across the Australian market.

TL;DR, Six Things Every Deal Team Must Know Now

• Mandatory notification. Acquisitions that meet prescribed monetary thresholds must be notified to the ACCC before completion. The voluntary informal-clearance era is over.
• Suspensory regime. Parties cannot close a notifiable transaction until the ACCC grants clearance or the statutory waiting period expires. Gun-jumping carries serious penalties.
• Phased commencement. The core mandatory regime started 1 January 2026; further changes to exemptions and procedural rules took effect 1 April 2026.
• Broader reach. The reforms capture share acquisitions, asset acquisitions, and certain minority investments that confer material influence, not just traditional majority buyouts.
• Designated sectors. Additional sector-specific thresholds apply in areas of concentrated market power, widening the net for transactions that might otherwise fall below general thresholds.
• Contract redesign required. Acquisition agreements must now include suspensive conditions, regulatory cooperation covenants, and reverse-break-fee mechanisms calibrated to the new clearance timelines.

Quick Decision Flow, Does My Transaction Trigger ACCC Merger Notification?

The first question any acquirer must answer under the new merger laws in Australia is whether the proposed transaction is notifiable. The following decision framework distils the statutory tests into a practical sequence of questions that deal teams should work through at the earliest stage of transaction planning.

Step-by-step decision questions

1. Is the acquirer or target connected to Australia? The regime applies where the target carries on business in Australia, holds assets in Australia, or supplies goods or services to Australian customers.
2. Does the transaction involve an acquisition of shares, assets or interests? The regime covers share acquisitions, asset purchases, long-term leases, and acquisitions of interests that confer material influence over the target’s competitive conduct.
3. Are the monetary thresholds met? Notification is required where prescribed turnover or transaction-value thresholds are satisfied. These thresholds are assessed on a consolidated group basis for both the acquirer and the target.
4. Does a designated-sector threshold apply? Lower or additional thresholds apply in sectors designated by the Minister, capturing transactions that would otherwise fall below the general monetary limits.
5. Is an exemption available? Certain categories of transactions are exempt, but exemptions were narrowed from 1 April 2026, so any assumed carve-out should be reassessed against the current rules.

Transaction type vs notification requirement

What the 2026 Merger Laws in Australia Require, Statutory Changes and Key Definitions

The Treasury Laws Amendment (Mergers and Acquisitions Reform) Act 2024 amended the Competition and Consumer Act 2010 (Cth) to replace the former voluntary, non-suspensory merger clearance process with a formal mandatory notification and suspensory clearance system administered by the ACCC. The legislative framework, developed through the Treasury’s competition-review process and passed through Parliament, represents a fundamental shift in Australian M&A rules.

Core elements of the new regime

• Mandatory notification. Parties to an acquisition that meets the prescribed thresholds must lodge a notification with the ACCC before completing the transaction. Failure to notify is a contravention carrying significant penalties.
• Suspensory obligation. Completion is prohibited until the ACCC has either cleared the transaction, the statutory review period has expired without a decision, or the parties have obtained authorisation from the Australian Competition Tribunal.
• Monetary thresholds. The regime prescribes turnover-based and transaction-value-based thresholds, assessed on a consolidated group basis. These thresholds are set by regulations and may be updated periodically by the Minister.
• Material influence test. The definition of “acquisition” is broad, capturing not only majority control but also acquisitions of interests that confer material influence over the target’s competitive conduct, a wider concept than the former “controlling interest” test.
• Designated sectors. The Minister may designate sectors in which lower notification thresholds apply, reflecting areas of concentrated market structure or particular public-interest sensitivity.
• Substantive test. The ACCC assesses whether the proposed acquisition would have the effect, or be likely to have the effect, of substantially lessening competition in any market in Australia.

Legislative timeline, key dates and their practical impact

ACCC Merger Notification Process, Steps, Timelines and Registers

The ACCC is the primary regulator responsible for reviewing notified transactions under Australia’s merger control framework. The ACCC maintains public merger registers that record notifications received, decisions made and the reasons for those decisions, providing transparency to market participants.

Filing and review process

1. Pre-notification engagement. The ACCC encourages parties to engage informally before lodging a formal notification, particularly for complex transactions or where competition concerns are anticipated. Early engagement can identify information requirements and reduce the risk of delays during the formal review.
2. Formal notification. The acquirer lodges a notification with the ACCC, providing prescribed information about the parties, the transaction structure, the relevant markets, and the competitive effects of the acquisition.
3. Initial review period. The ACCC conducts an initial assessment. If the ACCC is satisfied that the acquisition is not likely to substantially lessen competition, it may grant clearance at this stage.
4. Extended review. If competition concerns are identified, the ACCC may request further information and conduct a more detailed investigation, including market inquiries and engagement with third parties.
5. Decision. The ACCC either clears the transaction (with or without conditions), or declines to grant clearance. Parties whose notification is not cleared may seek review by the Australian Competition Tribunal.
6. Public register. The ACCC publishes its decision and reasoning on the public merger register, contributing to an evolving body of regulatory precedent that informs future notifications.

Typical timeline scenarios for merger clearance in Australia

Industry observers expect the ACCC to develop a “fast-track” clearance pathway for transactions that clearly fall below any competition concern, similar to Phase I processes in other mandatory-notification jurisdictions. The likely practical effect will be to reduce timing uncertainty for straightforward deals, but only where parties invest in thorough, front-loaded filings with complete data.

Practical Compliance Checklist for Deal Teams, Merger Laws Australia

Every acquirer and target operating under the reformed Australian M&A rules needs a structured compliance process that begins well before signing. The following checklist is designed for in-house counsel, CFOs and external advisers managing the notification workstream.

Pre-deal diligence and threshold assessment

• Map the consolidated group. Identify all entities in both the acquirer’s and target’s group for threshold-calculation purposes. Include controlled entities, funds under management (for PE acquirers), and portfolio companies with overlapping activities.
• Calculate turnover and transaction value. Apply the prescribed monetary thresholds to the most recent audited financial statements. For unlisted targets, commission an independent valuation early to avoid threshold disputes.
• Screen for designated sectors. Check whether the target operates in, or supplies goods or services to, any sector that the Minister has designated for lower notification thresholds.
• Assess material influence. Where the acquirer is taking a minority stake, map all rights that could confer material influence, board appointment rights, veto powers over competitive decisions, information rights, and any commercial arrangements.

Regulatory risk register and pre-notification strategy

• Build a competition risk register. Identify horizontal overlaps, vertical relationships and conglomerate effects. Estimate combined market shares in each affected market using publicly available data and internal records.
• Engage legal counsel experienced in ACCC processes. Competition counsel should assess whether pre-notification engagement with the ACCC is advisable and prepare a strategic engagement plan.
• Consider confidentiality. If the transaction is not yet public, discuss confidentiality protocols with the ACCC during pre-notification engagement. The ACCC has established procedures for handling confidential filings.
• Prepare the filing. Assemble prescribed information: transaction documents, market-share data, customer and supplier lists, internal documents discussing the competitive rationale, and any independent expert reports.

Signing-to-completion risk management

• Build ACCC clearance into the transaction timetable. Allow a minimum buffer of 90 business days from filing to anticipated clearance for moderately complex deals; longer for transactions in concentrated markets.
• Coordinate parallel regulatory approvals. If FIRB, ACCC, or sector-specific approvals are also required, sequence and coordinate these workstreams to avoid delays.
• Establish an information-response team. Designate internal resources to respond promptly to ACCC information requests, delays in responding extend the review period.
• Monitor interim compliance. During the suspensory period, the acquirer must not exercise influence over the target’s competitive conduct. Implement protocols to prevent premature integration or gun-jumping.

Transaction-Specific Guidance, Unlisted Targets, Private Equity and Minority Stakes

Unlisted acquisitions under Australia’s mandatory merger notification

The application of monetary thresholds to unlisted acquisition targets in Australia raises particular challenges. Unlike listed companies, where market capitalisation provides a readily observable metric, unlisted targets require valuation to determine whether thresholds are met. Deal teams should commission independent valuations early in the process and ensure the valuation methodology is defensible if queried by the ACCC.

Early indications suggest the ACCC will look through to the economic substance of the transaction when assessing thresholds, for example, aggregating the value of earn-out payments, deferred consideration and vendor financing into the transaction value. A conservative approach to threshold calculation is recommended: if there is any reasonable basis on which the thresholds might be met, notification should be considered.

Minority and minority-blocking stakes, when does material influence arise?

The material-influence test introduced by the reforms marks a significant expansion of merger control in Australia. Acquisitions of stakes well below 50% may trigger notification obligations if the stake, combined with other rights or circumstances, confers material influence over the target’s competitive conduct. Relevant factors include:

• The size of the stake relative to other shareholdings and the degree of share dispersion
• Board appointment or observer rights
• Veto rights over key competitive decisions (pricing, capacity, capital expenditure, market entry)
• Commercial relationships between the acquirer and target (supply agreements, licensing, JV participation)
• Access to competitively sensitive information

Industry observers expect the ACCC to develop detailed guidance on the material-influence test over time, drawing on enforcement experience. In the interim, deal teams should err on the side of caution and assess notification obligations wherever minority investments are accompanied by governance or commercial rights.

Private equity playbook, timing, conditionality and fund structuring

Private equity acquirers face particular challenges under the reformed regime. Fund timelines are often compressed, and the suspensory period introduces a new variable into deal execution. Practical steps for PE deal teams include:

• Threshold aggregation. Portfolio companies under common management or control may need to be aggregated when calculating whether thresholds are met. Map the entire fund group structure at the outset.
• Consortium bids. Where multiple funds co-invest, each fund’s existing portfolio in the relevant market must be assessed. Identify and disclose all overlapping portfolio activities.
• Break-fee calibration. The longer clearance timeline increases the risk of deal failure. Negotiate reverse break fees that reflect the ACCC timeline and compensate the seller for the extended exclusivity period.
• Interim operating covenants. Sellers will seek robust covenants protecting the target’s business during the review period. Balance these against the PE acquirer’s need for transparency on business performance.

Drafting Acquisition Agreement Clauses to Manage Merger Clearance Risk

The introduction of mandatory merger notification in Australia has made regulatory-clearance provisions one of the most heavily negotiated sections of acquisition agreements. Every deal that may trigger notification requires carefully drafted clauses addressing conditionality, risk allocation and interim governance.

Essential clause checklist

• Suspensive condition precedent. Completion must be conditional on ACCC clearance (or expiry of the statutory waiting period without a prohibition). Draft the condition broadly enough to capture clearance with conditions, and specify whether the acquirer is obligated to accept behavioural or structural remedies.
• Reverse break fee. The acquirer pays a reverse break fee to the seller if the transaction fails due to ACCC refusal. Negotiate the quantum based on the likely review timeline and the seller’s opportunity cost of the exclusivity period.
• Termination rights (long-stop date). Both parties should have the right to terminate if ACCC clearance has not been obtained by a specified long-stop date. Set the date realistically, early indications suggest a minimum of six months from signing for complex deals.
• Regulatory cooperation covenant. Require both parties to cooperate fully with the ACCC process, including providing information, attending meetings and using best (or reasonable) endeavours to obtain clearance.
• Interim operating covenants. The seller commits to operating the target in the ordinary course during the review period. Define “ordinary course” with specificity, major contracts, capital expenditure and key personnel changes typically require acquirer consent.
• Confidentiality and information barriers. Include clean-team arrangements to manage the exchange of competitively sensitive information between competitors during the review, preventing gun-jumping allegations.
• Seller warranties on competition matters. The seller warrants that it has disclosed all material information relevant to the competition assessment, including market-share data, customer relationships and any prior ACCC engagement.

Sample condition precedent clause framework

“Completion of the Transaction is conditional upon the ACCC either: (a) granting clearance for the Transaction under [relevant section] of the Competition and Consumer Act 2010 (Cth), with or without conditions acceptable to the Acquirer (acting reasonably); or (b) the statutory waiting period expiring without the ACCC having issued a notice of prohibition. If the ACCC Condition is not satisfied or waived by the Long-Stop Date, either party may terminate this Agreement by written notice.”

Enforcement, Penalties and Remedies, What Acquirers and Targets Must Fear

The consequences of non-compliance with Australia’s mandatory merger notification regime are severe and designed to deter both deliberate avoidance and inadvertent failures. The ACCC has broad enforcement powers under the reformed framework.

• Civil penalties. Failure to notify, or completing a notifiable transaction before clearance (gun-jumping), attracts significant civil pecuniary penalties. Penalties apply to both the acquirer and any officers knowingly involved in the contravention.
• Divestiture orders. Where a transaction has been completed in contravention of the regime, the ACCC can seek court orders requiring divestiture of the acquired business or assets, unwinding the transaction entirely.
• Interim injunctions. The ACCC may seek interim orders from the Federal Court to prevent completion or to preserve the competitive status quo pending resolution of enforcement proceedings.
• Reputational consequences. ACCC enforcement actions and the resulting public-register entries create lasting reputational risk for acquirers, particularly institutional investors and listed entities with ongoing regulatory relationships.

The practical message for deal teams is clear: where there is any doubt about whether a transaction is notifiable, the cost of notification is far lower than the cost of enforcement. Industry observers expect the ACCC to pursue early enforcement actions to establish the credibility of the new regime.

Practical Timelines, Key Dates for Merger Control in Australia

Conclusion, Next Steps for Acquirers and Targets Under Australia’s Merger Laws

Australia’s 2026 merger law reforms have fundamentally altered the regulatory environment for M&A and corporate finance transactions. The shift from voluntary informal clearance to mandatory, suspensory notification demands that every deal team, whether acting for a listed acquirer, a private-equity fund or a target board, reassesses its transaction processes, timetables and contractual frameworks.

The practical priority is clear. Acquirers should integrate ACCC threshold analysis into their earliest deal-evaluation processes and ensure that acquisition agreements are drafted to manage the new clearance timelines and risk allocation. Targets should understand their disclosure obligations and prepare for an active role in supporting the notification process. Both sides should invest in pre-notification engagement with the ACCC to reduce uncertainty and protect deal certainty.

For deal teams navigating specific transactions, bespoke advice from experienced Australian corporate finance and competition counsel is essential. The merger laws in Australia will continue to evolve as the ACCC develops its enforcement practice and publishes further guidance, staying current is not optional, it is a core deal-execution discipline.

Sources

1. ACCC, Mergers and acquisitions (official guidance)
2. Treasury, Mergers reform / explanatory materials
3. Parliamentary (APH) Bill page, Treasury Laws Amendment (Mergers and Acquisitions Reform)
4. ASIC, Corporate Finance Update Issue 28 (28 April 2026)
5. ACCC, Mergers registers
6. Allens, The future of mergers in Australia
7. Gilbert + Tobin, Merger reform legislation insights
8. Norton Rose Fulbright, Australia’s new mandatory merger control regime
9. Maddocks, Australia’s new merger notification regime