Australia's new mandatory merger control regime has now been in effect for six months. Since commencing on 1 January 2026, the regime has reshaped the way that merger filings are managed in Australia, introducing mandatory notification obligations, a suspensory standstill, and a level of regulatory process that has required significant adjustment for deal teams and their advisers. This update draws on the MinterEllison team's experience navigating the regime – in global and domestic transactions, across waiver filings, and Phase 1 and Phase 2 review processes.  

The regime has introduced considerable complexity. Merger parties have encountered teething problems as the ACCC embeds new processes and provides further guidance – this will continue for the foreseeable future. Substantive issues also remain with the structure and operation of the regime. While some issues are being addressed in a bill that has just been introduced to Parliament, other issues will likely need to wait for the 12-month review of the regime. 

This update includes an overview of our key reflections on the new regime, including some of the challenges that have arisen in practice. Further information is covered in the attached report. However, briefly, it is essential to note that:

1. Despite the complexity of the new regime and regulatory over capture, the ACCC is continuing to review transactions efficiently, and the pre-engagement process is being used flexibly, tailored to the specific deal.
2. Planning and preparation are critical. The new regime can be navigated efficiently, provided work is done early to plan for the clearance process and ensure that sufficient information is being frontloaded to enable the ACCC to make a decision promptly. 
3. The Government has introduced legislation that, if passed, is designed to address some of the key deficiencies in the regime that have been identified – particularly regarding the effect of declaring transactions to be automatically void if there is a failure to notify, and matters concerning joint control under the regime.  We have encountered various other issues concerning the scope of the notification thresholds and ambiguities with the exceptions.  It is likely that these issues will now need to wait until the 12-month review of the regime. 

Six months in, Australia's new merger control regime is bedding down but continues to present challenges. Important legislative reforms should, if they pass, address some (but not all) of the regime's more challenging features. Businesses should ensure they are accounting for the practical realities of the regime as it is operating and stay alert to further changes ahead. For advice on how the regime applies to your specific transaction, please contact our team.