Guidance

Interim measures and derogations in merger investigations

Guidance on how the Competition and Markets Authority (CMA) uses interim measures and derogations in merger investigations.

Documents

Interim measures in merger investigations (2025)

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Interim measures in merger investigations (2021)

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Derogation request template

Initial enforcement order template

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Initial enforcement order template

Details

This guidance for merging businesses and their advisers sets out how the CMA uses interim measures and derogations in merger investigations, including the: 

  • circumstances in which the CMA will require interim measures 
  • form that interim measures will typically take 
  • types of derogations that the CMA is likely (or unlikely) to grant 
  • timing for imposing and revoking interim measures, and granting derogations 

This guidance was updated to reflect changes to the mergers regime brought about by the Digital Markets, Competition and Consumers Act 2024.

Templates

The initial enforcement order template is used by the CMA as the basis for interim orders made by it under the Enterprise Act 2002 (as amended) in relation to completed mergers.

Merging businesses should use the derogation request template as a basis for the proposed consent letter granting the derogation that would be issued by the CMA.

Updates to this page

Published 28 June 2019
Last updated 23 June 2025 show all updates
  1. Summary for businesses published.

  2. Updated to reflect changes to the mergers regime brought about by the Digital Markets, Competition and Consumers Act 2024.

  3. Updated revised CMA108 guidance published.

  4. Updates to the Interim measures in merger investigations guidance and Initial enforcement order template following consultation.

  5. First published.

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