Mandatory Merger Clearance Process: ACCC Procedure and Timelines from 1 January 2026

From voluntary to mandatory

The Competition and Consumer Act 2010 (Cth) now includes a mandatory merger clearance regime following the insertion of Part XB by the Treasury Laws Amendment (Mergers and Acquisitions Reform) Act 2024. This regime, administered by the Australian Competition and Consumer Commission (ACCC), commenced on 1 January 2026. ACCC mergers clearance 2026 regime

Previously, businesses could voluntarily seek informal merger reviews. The new framework replaces this with mandatory pre-notification of notifiable acquisitions. Notification thresholds, determining which acquisitions are subject to the regime, are established by the Treasurer under section 51AKA, considering transaction value and combined Australian turnover.

A key feature of the mandatory regime is a suspensory effect. Notifiable acquisitions are prohibited from completing until clearance is granted by the ACCC or the relevant statutory review period has concluded. ACCC mergers clearance 2026 regime

Phase 1 review process

The initial assessment of a proposed merger is conducted during the Phase 1 review process. This phase has a default timeframe of 30 business days, commencing from the date the ACCC accepts a complete notification. During this period, the ACCC undertakes an initial assessment of the proposed merger and may consult with third parties, such as customers, competitors, and suppliers, through public notice.

At the conclusion of the Phase 1 review, the ACCC must make a decision. This decision will be one of three options: granting clearance for the merger to proceed, referring the matter to a more detailed Phase 2 review, or notifying the parties of a ‘put forward decision’ process.

The 30 business day timeframe for Phase 1 can be extended. This extension may occur if the parties to the notification agree to an extension, or if the notification submitted to the ACCC is initially incomplete. The ACCC anticipates that most merger notifications will be resolved within this Phase 1 review.

Phase 2 deep dive review

Phase 2 reviews are initiated when the ACCC identifies potentially substantial competition concerns following an initial assessment. This review period runs for a maximum of 90 business days from the date of referral. During this time, the ACCC undertakes a detailed examination of the proposed transaction, which may include economic analysis, commissioning expert reports, and conducting market inquiries.

Parties to a transaction under Phase 2 review have the opportunity to offer remedies to address any concerns raised by the ACCC. These commitments are considered as part of the assessment process.

At the conclusion of the Phase 2 review, the ACCC must issue a decision. This decision will be one of three options: clearance of the transaction, conditional clearance subject to accepted remedies, or a prohibition of the transaction. The standard 90 business day period for Phase 2 can be extended if all parties agree, or if the matter is deemed particularly significant.

Review and appeal

Decisions made by the ACCC under the new merger clearance process are subject to review. Review on the merits is available through the Competition Tribunal. An application for review must be lodged with the Tribunal within 14 days of the ACCC’s decision. The Tribunal has the power to affirm, vary, or set aside the ACCC’s decision.

Judicial review of ACCC decisions is also available, governed by the Administrative Decisions (Judicial Review) Act 1977. This provides an alternative avenue for challenging ACCC determinations.

Filing fees associated with notifications are determined by transaction size. The ACCC publishes an annual fee schedule outlining the current fee structure.