Can my small Polish shop join a claim for supplier price-fixing, and what evidence do I need?

Dear Sir/Madam,

In response to your inquiry regarding the possibility of a small Polish shop joining a collective lawsuit concerning a suspected price-fixing cartel by a supplier, I hereby clarify the key procedural and substantive issues below.

Appropriate Procedural Path
In the case of suspected price-fixing (an agreement restricting competition), direct claims in civil proceedings before the common court are not appropriate. First, proceedings before the President of the Office of Competition and Consumer Protection (UOKiK) must be initiated by filing a notification of suspected restrictive practices. Based on the decision of this authority (e.g., confirming the violation), compensation may subsequently be sought civilly from the wholesaler for damages incurred in the business.

Legal Basis
Pursuant to the Act of 16 February 2007 on Competition and Consumer Protection (consolidated text, Journal of Laws of 2025, item 1714), any person may submit a written notification to the President of UOKiK regarding suspected practices restricting competition (Article 86(1)) or infringing collective consumer interests (Article 100(1)). The notification should include, among others: identification of the undertaking (wholesaler), description of the factual situation (identical prices and discount terms among competitors), the violated provision (e.g., Article 6(1)(1) of the Act), substantiation of the violation, and the notifier's details; all evidentiary documents must be attached (Article 86(2,3)). The President of UOKiK informs about the manner of consideration within the timeframe specified in the Code of Administrative Procedure (Article 86(4) and Article 100(3)).

Required Documents for Notification
Attach to the notification: invoices, emails showing sudden price changes, price lists, correspondence (including SMS, WhatsApp, and meeting notes), tender announcements (if applicable), and other evidence substantiating the cartel.

Course of Proceedings before UOKiK
The President of UOKiK conducts explanatory proceedings (regarding suspicion of violation, without parties or charges; possible requests for documents, inspections, searches). If suspicions are confirmed, antimonopoly proceedings are initiated (against the wholesaler as a party; with rights to access files, submit evidence, and present a position). The outcome may be a decision confirming the violation, a fine up to 10% of turnover, or a settlement (e.g., voluntary penalty submission with reduction).

I recommend cooperating with an attorney specializing in competition law to prepare the notification; your invoices and emails form a solid basis. Please note that this explanation does not constitute legal advice nor an offer within the meaning of applicable law.