Big CAT Watch

The UK Competition Appeal Tribunal (the CAT) is dealing with some enormous pieces of litigation as part of its competition collective action regime. 

These big claims have become the pride of the CAT and the main event in UK collective redress. But developments in collective proceedings can happen quickly and quietly and keeping track of them can feel like herding cats.

Big CAT Watch is our new platform containing data and analysis on UK collective proceedings. Our Big CAT Watch visualisations chew through the complexity and show you what you need to know about UK collective proceedings.

The information in this analysis is updated at the start of each month. It was last updated on 1 September 2025. The information is taken from documents published on the CAT’s website, so new applications will not be included until the CAT publishes them.

The Big CAT Watch charts below show collective proceedings applications broken down by:

• Certification Status
• Opt-in / Opt-out
• Standalone / Follow-on
• Infringement Type
• Industrial Sector