Serial Killers? Australia’s New Merger Rules Take Aim At Roll‑ups

This article is a continuation of Walter Baden’s May 2025 article outlining Australia’s move to mandatory merger notification in 2026. That regime is now in place.

This article focuses on how the regime operates in practice for serial or “creeping” acquisitions, particularly roll‑up strategies. Multiple smaller deals can now be aggregated, triggering notification and delaying completion until cleared by Australia’s competition regulator, the Australian Competition and Consumer Commission (ACCC).

Against that backdrop, the key feature for roll‑ups is aggregation. Acquisitions in the same or related markets over a rolling three‑year period are bundled such that the regulatory lens no longer rests on individual transactions viewed in isolation. Instead, patterns of acquisition are examined collectively, reflecting the ACCC’s policy view that incremental consolidation can reshape markets just as effectively as a single large transaction, only more quietly.

The notification thresholds for creeping acquisitions are set out in the table on the next page.

Previously notified acquisitions are added to the subject acquisition revenue when calculating thresholds, subject to limited exceptions.

Walter Baden’s recent transaction experience illustrates how these changes might play out in practice. Walter Baden has acted for UK and Japanese acquirers who recently have pursued acquisition programmes targeting Australian businesses in the engineering services and recruitment sectors, industries both highly fragmented and traditionally well‑suited to roll‑up strategies. Individually, none of these transactions would cross the new merger control thresholds. Collectively, however, future acquisitions for these clients are increasingly likely to do so, bringing them firmly within the ACCC’s purview.

The practical consequences are material. Acquisition sequencing becomes more complex, deal documentation must accommodate mandatory waiting and approval periods, and Australian revenue monitoring becomes key. Setting the deal timetable, once largely controlled by the parties, now must account for the ACCC’s involvement. Parties will also need to budget for additional deal costs with filing fees ranging from AUD 8,300 for waiver requests to around AUD 56,800 for standard Phase 1 assessments, and up to AUD 1.595 million for complex Phase 2 assessments. Together with adviser fees, the ACCC’s fees become a major deal expense.

The reforms do not prevent acquisition‑led growth, but they do require earlier planning and regard to prior transactions. In Australia’s new merger control world, it is not just the next deal that matters, it is the entire series. And the ACCC, unlike the parties, will not lose sight of prior transactions.