The retail banking market in Sweden is highly concentrated and oligopolistic. This has been confirmed by numerous reports from different competition authorities within the EU, for example the Swedish competition authority. A considerably high number of different sorts of competition barriers has been pointed out in these reports. The competition barriers are mainly directed to the smaller banks and the potential competition. The retail banking market in Sweden is dominated by four major banks, which together has over 80 percent of all market shares. These four dominating banks more or less control the payment systems and have a great deal of influence within the payment systems. It is necessary for all banks to be able to take part of the payment systems. The control that the four dominants have over the payment systems has been more significant considering their cooperation in so called infrastructure clubs. It is these clubs that have formed the conditions in every contract between the infrastructure club members and other smaller banks, who wants to be able to provide their customers a diversity of banking services. The dominating banks purpose with this infrastructure cooperation is to lower the network-expenses for the owners and to provide a more effective network-system. According to my results, these infrastructure clubs could help create a harder market climate and higher entry barriers for non-members than what ought to be considered as normal for such a market climate. Smaller banks who want to provide a variety of services, so called full-service banks, meet the hardest obstacles to overcome. Therefore there has not started a new full-service bank since 1993. The almost only payment system which the four dominants do not control is Riksbankens payment system “RIX”. The European commission has many different criteria in their search for different violations of abuse and dominant position. I have used nine of these in my paper. Eight of these criteria were concordant with my results whether or not connections exist to abuse and dominant position. My results have pointed out some problems that could be in dispute with Swedish competition law, considering the market position and the key role the members in an infrastructure club possesses. Despite the fact that detailed decisions from the European court of Justice (ECJ) especially obliges dominants to protect and not to distort competition in any way exists, my opinion is that there could be some parallels to a distorted competition on the Swedish retail banking market. Furthermore, the three different steps within the payment system are represented through the dominants participation when they are members in the same infrastructure club. This gives the result that their cooperation is vertically integrated. The cooperation involves important information about the member’s financial strengths and their ability to compete as a market actor, but also information of great importance of the infrastructure and its development and further efficiency. According to my results, the economical cooperation that the members of the infrastructure clubs have, could not be referred to as an “economic entity” in the same way as the ECJ used it regarding their investigations of collective dominance. The dominants cooperation, according to me, is better described as a collective behavior. The dominants cooperation in these infrastructure clubs could also be of that character as referred to in 6 § konkurrenslagen. I do not consider the payment systems owned by the dominants to have the same character as “essential facilities”, since smaller niched banks have entered the market and thus have chosen other channels than the dominants payment systems to reach their customers. I also have the opinion that every effect caused by the cooperation between the dominants could not be defendable as acceptable objective grounds. Due to the above mentioned arguments, I find it sensible to investigate further whether or not the dominants purpose with their infrastructure club is concordant with its means.