Few Surprises, As The CMA Finalises Its Revised Approach To Merger Efficiencies

After launching a review process at the beginning of 2026, and publishing draft guidance for consultation in June, the CMA has now formalised its new approach to the assessment of efficiencies arguments in merger control cases. The new approach is set out in chapter 8 of the CMA’s revised merger assessment guidelines.

The CMA’s review of its approach to merger efficiencies was launched as part of its ongoing 4Ps initiative, aimed at improving the pace, predictability, proportionality, and process of its enforcement work.

In our previous article on this topic, we explored in detail the CMA’s draft revised guidance on the assessment of Rivalry-Enhancing Efficiencies (REEs), which took into account the feedback received in response to the CMA’s initial call for evidence. The new final guidance, which will apply to all cases in which the formal Phase 1 investigation commenced on or after the publication date of 3 September 2026, is largely unchanged from the draft version.