The International Register
In Belgium, collective actions are registered at the official government website, with a full list available here.
In Germany, you can find more information about collective actions at:
KapMuG (Investor Model Procedure Act)
Musterfeststellungsklage (Consumer Model Declaratory Action)
In Italy, collective actions are registered on the Online Services – Judicial Office portal, via the Italian Ministry of Justice, with a full list available here.
In the Netherlands, collective actions are registered at the Central Register for Collective Claims, with a full list available here.
In Poland, collective actions are registered at official portal of the Ministry of Justice, with a full list available here.
Popular actions do not have a special register in Portugal. Civil actions are published on the Citius website, in the distribution of new cases section and during this short period (a few months only).
In Slovenia, collective actions are registered at official government website, with a full list available here.
The Competition Appeal Tribunal
The United Kingdom Competition Appeal Tribunal is a specialist judicial body with cross-disciplinary expertise in law, economics, business and accountancy which hears and decides cases involving competition or economic regulatory issues.
It contains namely collective cases brought and decisions handed within the Competition private enforcement scope on an opt-in or on an opt-out basis, according to Section 47b Competition Act.
The United Kingdom lists and informs about Group actions “which give rise to common or related issues of fact or law” and engaged according to r19.10 of the Civil Procedure Rules.
Representative actions are not registered as such. See for instance TikTok the case.