How merger reviews work at the FTC, EU and CMA
Large deals are often reviewed by competition authorities before they can close. The US, EU and UK systems differ in whether notice is required, how long reviews take and what the authority can do.
- In the US, parties to large deals file premerger notice with the FTC and the Justice Department, and one agency reviews the deal. They generally must wait 30 days before closing.1
- If the US agency needs more information it issues a Second Request, which extends the waiting period. It can then close the investigation, accept a consent agreement, or seek a preliminary injunction in federal court.1
- In the EU, notification is mandatory for concentrations with a Community dimension. The European Commission has 25 working days in Phase I and, if concerns remain, 90 working days in a Phase II in depth investigation.2
- The Commission can clear a deal unconditionally, clear it subject to commitments offered by the parties, or prohibit it. Its decisions can be reviewed by the General Court and the Court of Justice.2
- In the UK, merger notification to the CMA is voluntary, but the CMA can investigate completed mergers that were not notified. Once a merger notice is complete, the formal phase 1 investigation must finish within 40 working days.3
- The CMA's guidance on jurisdiction and procedure, known as CMA2, sets out the full phase 1 and phase 2 process. It was last updated on 19 December 2025, after an earlier update on 28 October 2025.4
Sources
- US Federal Trade Commission, Premerger Notification and the Merger Review Process (28 October 2026)
- European Commission, Directorate General for Competition, Mergers: Procedures (28 October 2026)
- UK Competition and Markets Authority, Mergers: how to notify the CMA of a merger (12 November 2024)
- UK Competition and Markets Authority, Mergers: guidance on the CMA's jurisdiction and procedure (CMA2) (19 December 2025)