For nearly a decade we have been conducting in Markiewicz and Sroczyński cases of the so-called shelf charges as acts of unfair competition. Most often we defend against allegations that quantity discounts are prohibited (according to the sales principle: you buy more, you get a lower price per item). Often these discounts can only be settled retroactively, because it is not known in advance how much goods will be purchased by the chain of shops. This is where suppliers’ claims most often come into play. We are witnessing the evolution of judgments in these cases. Jarosław Sroczyński and Marcin Mioduszewski, legal adviser, also made a commentary on Article 15(1)(4) (and other provisions) of the Act on Combating Unfair Competition for Wolters Kluwer Polska. The current line of jurisprudence is well over 90% of retrospective discounts admitted. In a case in which we represented a retail chain, last Friday the Court of Appeal in Warsaw again found in favour of us, stating that such a rebate on turnover is not prohibited. However, for the first time the court referred, and approvingly, to our argument (Marcin Mioduszewski, Jarosław Sroczyński, Klaudia Wojakowska-Grochot and Zuza Ochońska) that negotiating a rebate is not an obligation at all. In other words: the retail chain, can simply present its offer or sales conditions, to which the supplier will agree or not (adhesion contract). Perhaps business logic dictates that this should be the case, but in the case law of the courts this has not been so obvious.