ACCC merger clearance reforms: How does the transition period affect your deal?

From 1 January 2026, merger parties that trigger defined thresholds must notify the ACCC and obtain clearance prior to completion, or substantial penalties will apply. The final thresholds have not yet been released, however we have summarised the Government's intended thresholds here.

Merger parties need to start thinking now about how the new regime affects them as it will apply to transactions that complete on or after 1 January 2026 – meaning deals being negotiated now may require clearance under the new regime if not completed by 31 December 2025.

The ACCC recently released transitional guidelines on how it will manage the transition to the new regime. The key points for the phasing out of the current informal clearance regime are as follows:

1. October 2025 is the practical deadline to make informal clearance requests under the current system: Requests for informal clearance lodged after 1 October 2025 – even where there are limited or no competition risks – may not be considered by the ACCC before 31 December 2025, and the ACCC will not continue the review if it has not been finalised by 31 December 2025. If this happens, the deal will need to be notified under the new regime if it meets the notification thresholds.
2. For deals cleared under the informal clearance regime before 1 July 2025 that do not close before 1 January 2026, it is possible to request an updated clearance letter if that request is made by early October. If granted, notification under the new regime won't be required: If the ACCC has pre-assessed or indicated that it will not oppose the acquisition before 1 July 2025 but the transaction will not be put into effect before 1 January 2026, it will be possible to request an updated informal view for the purpose of obtaining a contemporaneous letter that the ACCC does not intend to take action, provided the ACCC maintains their original view and the request is made by early October 2025. Receiving this letter will mean the parties won't have to notify the acquisition under the new regime, as long as it is put into effect within 12 months of the date of the letter.
3. Deals cleared between 1 July 2025 and 31 December 2025 must close within 12 months of the date of clearance: If an acquisition is pre-assessed or is not opposed by the ACCC between 1 July 2025 and 31 December 2025, there will be no need to notify under the new regime so long as the parties have received a clearance letter from the ACCC and the acquisition is put into effect within 12 months of the date of the clearance letter.
4. Deals cleared between 1 July 2025 and 31 December 2025 that don't close within 12 months of clearance will need to be re-notified: If an acquisition has received clearance within this time frame but is not put into effect within 12 months of receiving such notification from the ACCC (and is a notifiable acquisition that meets the notification thresholds), then the acquisition will need to be re-notified under the new regime.

What does the transition period mean for your deal?

Every deal is unique and there are a number of factors that should be considered when making a decision about how to approach ACCC clearance for your transaction.

My deal is being reviewed by the ACCC and I think it will be cleared soon. I don't need to worry about the new system, right?

If your deal is informally cleared by the ACCC before July 2025:

• You do not need to notify under the new system unless your deal will not close by 31 December 2025. If your deal will not close by December, from 1 July 2025 onwards, merger parties can request an updated informal view by way of a letter from the ACCC, to confirm the ACCC maintains its original view. As long as the deal completes within 12 months of the date of that new letter, parties do not need to re-notify their deal under the new system. The ACCC has advised that these requests for an updated view should be made by early October 2025 and otherwise, as early as possible, to ensure they can be processed in time.

If your deal is informally cleared by the ACCC between July and December 2025:

• You do not need to notify under the new system unless your deal does not close within 12 months of receiving that advice from the ACCC. If your deal does not close within 12 months of clearance, you will need to re-notify or seek a waiver under the new system if the thresholds are satisfied.

Can I still seek informal clearance under the existing system after July 2025?

The informal clearance system will remain open until 31 December 2025. If you receive informal clearance on or after 1 July, you will not need to notify under the new regime. If the deal is not cleared by 31 December 2025 or does not close within 12 months of clearance, then if it meets the thresholds you will need to re-notify under the ACCC's new system or apply for a waiver. The ACCC has advised that deals notified under the existing system after October 2025 – even those with limited or no competition risks – may not be reviewed by the 31 December deadline. We recommend seeking advice on likely review timeframes before deciding whether to seek informal clearance or to notify voluntarily under the new regime, which will be available from 1 July 2025.

My deal will sign in the second half of this year, and will definitely close within 12 months. Does that mean I can seek informal clearance under the existing system any time until the end of 2025?

Using the existing informal clearance system in the second half of the year is not guaranteed to provide an ACCC clearance before the end of the year, depending on the complexity of the case as well as the volume of cases before the ACCC. The ACCC has advised that requests for review after 1 October 2025 may risk not being considered in time, even for deals with limited or no competition risks. If the ACCC has only partially reviewed your transaction by 31 December 2025, it will need to be re-notified under the new regime, which may lengthen the overall review period. The ACCC has indicated that it will try to move partially considered deals through the new system more quickly, to reflect work already undertaken, where appropriate.

We recommend seeking advice on likely review timeframes before deciding whether to seek informal clearance or to notify voluntarily under the new regime, which will be available from 1 July 2025.

My deal doesn't meet the new thresholds, that means I don't need to notify the ACCC, right?

Deals that don't meet the thresholds will not be subject to the obligation to notify, and the requirement to obtain clearance prior to completion, under the new regime.

However, the broad prohibition on acquisitions which have the purpose, effect or likely effect of substantially lessening competition in section 50 of the Competition and Consumer Act 2010 will continue to apply to deals that are not notified under the new regime. The ACCC will retain its existing powers to investigate and bring proceedings in the Federal Court in the event of a suspected breach. At the ACCC's compliance and enforcement priorities update 2025-26 address, the ACCC Chair said that the ACCC "will continue to investigate and take action against mergers that we consider are likely to substantially lessen competition under this provision." Even if a deal falls below the thresholds, if the transaction will result in an increase in concentration, we recommend seeking advice on whether and how to engage with the ACCC.

My deal reaches the thresholds of the new system, but it doesn't raise any competition issues, what should I do?

If you are able to close before 1 January 2026, you will not be required to notify under the new regime. If your deal does not close by that time, you will either need to notify or apply for a waiver from the ACCC. Under the new regime, notified deals that do not raise competition issues may be reviewed under the "fast track" process (described below).

What happens if I obtain a waiver under the new system?

Notification waiver applications under the new system may be made on or after 1 January 2026 (but are not available before that date even if you opt-in to the new system). If you obtain a waiver, you will be exempted from the requirement to notify and to obtain clearance prior to completion. You should however be aware that the prohibition on acquisitions which have the purpose, effect or likely effect of substantially lessening competition (section 50 of the Competition and Consumer Act 2010) continues to apply. In other words, the ACCC could technically commence court proceedings if it considered that the transaction breached section 50 – although this is very unlikely if a waiver has been granted.

An exemption to section 50 applies to transactions notified under the new regime, but not those which are the subject of a waiver. The ACCC will provide further guidelines on waivers later in 2025.

My deal requires FIRB approval. Do the merger clearance reforms impact the FIRB application process?

These new reforms do not directly influence the FIRB regime and we expect FIRB to continue consulting with the ACCC on transactions notified to FIRB. Under the new ACCC regime, transactions involving foreign investments may require approvals from both the ACCC and FIRB, potentially increasing regulatory scrutiny and complexity for investors. Transactions involving foreign investments that do not require notification under the new merger control regime but which require FIRB approval may still require de facto ACCC clearance, as is the case under the current system.

I've decided to voluntarily use the new system: How long will it take the ACCC to make a decision?

While there are statutory time limits under the new regime, the ACCC will be responsible for advising parties of the "Effective Notification Date" (ie. Day 0). In practice this is likely to mean that the statutory clock will only start once the ACCC is satisfied that it has received the complete set of information needed to start its review. It is unclear how extensive and detailed any discussions with (and requests from) the ACCC will be, during this pre-notification period.

Following the Effective Notification Date, the statutory time limits will be as follows:

• Phase 1 determination: 30 business days (although a fast-track determination may be made after 15 business days for cases where no concerns are identified).
• Phase 2 determination: 90 business days.

These timeframes may be extended in a range of circumstances, including where:

• there are remedies proposed;
• there are material changes of fact; or
• a notification to the ACCC is incomplete or misleading.

If the ACCC does not make a determination within the statutory time limit (as extended), it will be deemed to have made a decision that the transaction may be put into effect.

More details to come

More information about the regime is yet to be published, including: the process of obtaining a waiver and the final thresholds. We will publish more practical guidance as this information comes to hand.