This critical commentary on the judgement of the Polish Supreme Court concerns the analysis of the application of the contra proferentem rule in the interpretation of contracts with non-consumers which is highly debatable due to the literal content of the Polish Civil Code. The issue is particularly important when it comes to adhesive contracts with dominant entities such as banks, so this judgment is an opportunity to argue in favor of the wider application of the mentioned rule. The main subject of the commentary is to prove that the regulation of the bank account contract is anachronistic and should be modernized. The current regulation is not in line with modern economics while calling the bank activity by using the notion of "circulating the money" deposited in the bank account. That point of view does not take into account the role which banks play in money creation and how banks are taking on deposits and granting loans and credits. From the economical point of view, there is no such occurrence as "circulation" in the meaning used by the Supreme Court. Those circumstances should be considered in an analysis of the bank account contract and lead to the conclusion that the bank is not limited by the attachment of a bank account. As the result, the interest resulting from the contract should be paid to the customer even for the period when the bank account was attached.