Draft revised guidance on our approach to assessing merger efficiencies
Overview
The CMA has been delivering a programme of work to embed our 4Ps framework – pace, predictability, proportionality, and process – across our merger control function.
In January 2026, we launched a review into our approach to the assessment of rivalry-enhancing efficiencies in mergers. We are now consulting on proposed updates to our guidelines.
We have published:
- draft revised guidance, which is intended to replace the text currently in paragraphs 8.2 to 8.27 of our Merger Assessment Guidelines
- a consultation document, which summarises the key changes proposed in the draft revised guidance
Both documents are available at the bottom of this page.
We have also published the responses to our call for evidence.
What are 'rivalry-enhancing efficiencies' in mergers?
Rivalry-enhancing efficiencies are merger-specific benefits that can increase the competitiveness of a business – for example, by reducing its marginal costs or improving the ability and/or incentive to innovate.
In some cases, efficiencies can address the CMA's concerns about the potential anticompetitive effects of a merger.
Why your views matter
The draft revised guidance is intended to give more detail and clarity on our analytical approach to rivalry-enhancing efficiencies, and on our process for assessing efficiencies.
We're seeking your views on whether these changes are:
- sufficiently clear and useful
- consistent with our 4Ps framework
We also welcome any other suggestions regarding the content of the draft revised guidance.
Your views will help us shape the final revised guidance. Please email your response to mergerefficienciesreview@cma.gov.uk or use the form below.
Interests
- Mergers