Guidance
Merging your business
What to do if you're thinking about a merger, or already going through a merger investigation.
The Competition and Markets Authority (CMA) investigates some mergers and assesses how they could affect competition in the UK.
This page links to helpful information if you:
- are thinking about merging your business with another one
- have recently started or completed a merger
- are already involved in a CMA merger investigation
What you need to know
| How mergers are investigated | What happens if we investigate your merger, and how long it takes |
| How we’ll engage with you | How we’ll engage with you and your advisors during an investigation |
| Interim measures | How we might impose temporary restrictions before or while we investigate your merger |
Tell us about a merger
| Notify a merger to us | How to tell the CMA about a planned or completed merger, and why this matters |
| Merger notice forms | Use these forms to notify your merger to us |
If we’re investigating your merger
| Internal document requests | When and how we might request internal documents from you during our investigation |
| Remedies | How we might choose, design and implement remedies, if we have concerns about your merger |
| Propose remedies at phase 1 | Use this form to propose remedies (or ‘undertakings in lieu of reference’) during a phase 1 investigation |
| Propose remedies at phase 2 | Use this form to propose remedies during a phase 2 investigation |
Updates to this page
Published 10 June 2025