Australia ends 50-year era of voluntary merger review

Overview

For half a century, Australian companies could merge at will and simply inform regulators afterward. That ended January 1, 2026. Now businesses must notify the Australian Competition and Consumer Commission before closing deals that meet certain thresholds—and wait for approval. Miss the requirement and your acquisition is automatically void, with penalties on top.

The shift targets what regulators call 'creeping acquisitions'—serial buyers, especially private equity firms, rolling up competitors one at a time. Australia joins the EU, US, and most developed economies in requiring mandatory pre-merger notification. The ACCC expects to decide 80% of cases within three weeks. The other 20% face deeper scrutiny in a country where regulators blocked major healthcare and toll road consolidations in recent years.

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Key Indicators

50 years

Duration of voluntary regime

Longest-running voluntary merger system among major economies

$200M

Combined revenue threshold

Minimum combined Australian revenue triggering mandatory notification

$250M

Transaction value threshold

Alternative global transaction value trigger for notification

80%

Fast-track decisions

Share of acquisitions ACCC expects to clear within 15-20 business days

3 years

Serial acquisition window

Lookback period for aggregating prior acquisitions by same buyer

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People Involved

Gina Cass-Gottlieb

Leading implementation of mandatory merger regime

Rod Sims

Initiated merger reform campaign

Organizations Involved

Australian Competition and Consumer Commission

Federal Regulatory Agency

Primary enforcement authority under new regime

Australia's competition and consumer protection regulator with powers to review and block anticompetitive mergers.

Business Council of Australia

Industry Association

Engaged in reform consultation with concerns about red tape

Peak body representing Australia's largest companies, advocating for business-friendly policy.

Law Council of Australia

Professional Association

Expressed skepticism about regulatory discretion

National representative body for the Australian legal profession.

Timeline

Mandatory Merger Control Takes Effect
Implementation

Core regime launches: qualifying acquisitions now require ACCC pre-approval. Deals closed without clearance automatically void.
January 1st, 2026
Government Delays Asset Threshold Rules
Policy Adjustment

Treasury announces asset acquisition and control thresholds postponed to April 1, 2026, giving businesses more preparation time.
December 1st, 2025
Voluntary Notification Period Begins
Implementation

Companies can voluntarily notify acquisitions under new system during six-month transition period.
July 1st, 2025
Parliament Passes Merger Reform
Legislative

Senate approves bill with no amendments, ending 50-year voluntary merger review system.
November 28th, 2024
Bill Passes House of Representatives
Legislative

Treasury Laws Amendment (Mergers and Acquisitions Reform) Bill 2024 clears lower house with four Senate sitting days remaining.
November 21st, 2024
Treasury Laws Amendment Bill Introduced
Legislative

Government introduces merger reform legislation to Parliament; Senate Economics Committee given until November 13 to report.
October 10th, 2024
Major Healthcare Merger Blocked
Enforcement

ACCC prevents Australian Clinical Labs' acquisition of Healius, second- and third-largest pathology providers.
December 1st, 2023
ACCC Opposes Transurban Toll Road Acquisition
Enforcement

Regulator blocks Transurban's acquisition of Horizon Roads, citing entrenchment concerns in Victoria.
September 1st, 2023
Cass-Gottlieb Details Proposed Thresholds
Policy Announcement

ACCC Chair outlines monetary and market-share thresholds at National Press Club, emphasizing focus on 'mergers that matter.'
April 12th, 2023
Leadership Transition at ACCC
Personnel

Gina Cass-Gottlieb succeeds Rod Sims as ACCC Chair, continuing push for merger reform.
March 22nd, 2022
ACCC Chair Sims Launches Reform Campaign
Policy Advocacy

Rod Sims publicly calls for mandatory merger clearance regime, arguing Australia's laws are 'flawed' and 'out of step' internationally.
April 1st, 2021

Scenarios

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ACCC Becomes More Aggressive, Blocking Wave of Deals

Armed with administrative approval power, the ACCC significantly increases intervention rates beyond the historical norm. Healthcare consolidation, private equity roll-ups, and supermarket expansions face routine blocks or demanding behavioral undertakings. Deal volume drops as acquirers avoid notification-triggering thresholds. Business groups pressure government for threshold increases and expedited review timelines. The regime's success depends on ACCC resources—if case backlogs develop, the 80% fast-track target becomes fiction.

Discussed by: Competition law firms including Gilbert + Tobin, Clayton Utz, and Ashurst analyzing enforcement trends

Consensus —

Steady Implementation, 80% Cleared Quickly as Promised

The ACCC hits its targets: most deals clear in three weeks, intervention focuses on genuinely problematic transactions. Serial acquisition provisions catch private equity firms building healthcare and retail empires but don't chill routine M&A. Foreign investors adapt to dual ACCC-FIRB review. After initial compliance learning curve, the regime settles into predictability. Australia joins the global norm without major disruption—voluntary notification worked informally for decades; mandatory rules simply formalize existing practice.

Discussed by: ACCC guidance documents and regulatory forecasts from White & Case, Norton Rose Fulbright

Consensus —

Thresholds Prove Too Broad, Triggering Reform Pressure

The $50 million cumulative acquisition threshold for serial buyers sweeps in immaterial deals, forcing ACCC notification for transactions with zero competitive impact. Small businesses buying competitors for $2-5 million face mandatory filings and delays. Compliance costs hit mid-market M&A disproportionately. Within two years, Parliament raises thresholds or creates categorical exemptions. The April 2026 delay of asset thresholds becomes permanent. Overreach undermines the reform's legitimacy, forcing ACCC to grant waivers routinely—recreating informal discretion the law was meant to eliminate.

Discussed by: Business Council of Australia and Law Council submissions warn of over-capture risks

Consensus —

Historical Context

US Hart-Scott-Rodino Act (1976)

1976

What Happened

The United States pioneered mandatory pre-merger notification with the Hart-Scott-Rodino Antitrust Improvements Act. Before 1976, US antitrust enforcement was purely reactive—agencies challenged deals after closing, often too late to unwind them. HSR required companies meeting size thresholds to notify the FTC and DOJ and wait 30 days before closing. Failure to file brought penalties exceeding $50,000 per day.

Outcome

Short Term

Initial business resistance focused on compliance burdens and waiting periods for routine deals.

Long Term

Became global template for merger control. Regulators gained ability to investigate before deals closed, dramatically improving enforcement effectiveness. Nearly 50 years later, most developed economies operate similar mandatory notification systems.

Why It's Relevant Today

Australia's reform follows the HSR playbook exactly: shift from post-transaction challenges to pre-approval, cite enforcement gaps under voluntary system, promise fast clearance for non-problematic deals.

EU Merger Regulation (1989)

1989-2004

What Happened

The European Commission gained merger control authority in 1989 as part of building the single market. Before that, member states handled merger review inconsistently. The 1989 regulation created mandatory notification for deals above specified turnover thresholds and suspensory rules—companies couldn't close until cleared. After the Commission lost court challenges in the early 2000s, it reformed the system in 2004 with more rigorous economic analysis.

Outcome

Short Term

Businesses adapted to dual-track review: EU-level for large cross-border deals, national authorities for smaller domestic transactions.

Long Term

The EU regime became the world's most influential merger control system alongside the US. The 'more economics' approach from the 2004 reform set standards globally. Most countries adopting merger control since 1990 use EU-style mandatory notification with turnover thresholds.

Why It's Relevant Today

Australia's ACCC explicitly modeled its thresholds and two-phase review process on EU precedent. Cass-Gottlieb's goal: bring Australia from outlier to international norm.

UK Digital Markets Act (2025)

2025

What Happened

On January 1, 2025, the UK implemented its most significant competition reform in 20 years. While maintaining a generally voluntary merger regime, the Digital Markets, Competition and Consumers Act created mandatory notification requirements for Strategic Market Status firms acquiring stakes above 15%, 25%, or 50% in targets exceeding £25 million value. The reform raised general CMA review thresholds from £70 million to £100 million and expanded the agency's investigative powers.

Outcome

Short Term

The UK carved out a middle path: voluntary notification remains the default, but tech 'gatekeepers' face mandatory pre-approval for acquisitions.

Long Term

Test case for targeted mandatory notification focused on specific sectors and firm types rather than economy-wide thresholds. If successful, other jurisdictions may adopt hybrid models.

Why It's Relevant Today

Australia and UK moved simultaneously toward tighter merger control, but chose opposite strategies. UK targeted Big Tech while preserving voluntary filing. Australia went comprehensive mandatory notification. Both responded to the same concern: voluntary systems let problematic deals slip through.