Abstract

Public procurement contracts are civil law contracts and are subject to the provisions of the Civil Code. Due to the principles governing the public procurement system they are subject to certain restrictions, inter alia concerning objective modifications of those contracts. The civil law has worked out certain rules as to the objective changes, whose permissibility arises from the applicable principle of the freedom of contracts. However, as regards public procurement this principle is subject to substantial restrictions. This is aimed at preventing the situations whereby the contents of the awarded contract would be essentially different from that established under the proceedings leading to the selection of a contractor. For this reason, Art. 144.1 of the Public Procurement Act allows for such changes only when such possibility was foreseen and its conditions were put down by the contracting authority in advance. Changes made in violation of that restriction are invalid. However, this concerns only such changes which are specified by the Act as significant, which include, without limitation, those relating to the essential aspects of a contract (essentialia negotii).

It is frequently necessary to change the contents of a contract because of a change of applicable tax regulations, in particular the VAT. It is commonly viewed that a change of this kind is not an essential one as it does not undermine the principle of competitiveness. Therefore, it is admissible in the light of Art. 144.1 of the Public Procurement Act. However, it requires that both parties give their consent. Should a party fail to give its consent, it is possible to take the matter to court and request the commitment to be modified under Art. 357¹ of the Civil Code (so-called rebus sic stantibus clause).

The rebus sic stantibus clause may also be applied in other cases of extraordinary modification of terms. However, this always requires judicial intervention. On the other hand, it seems that to a certain limit the parties should have at their disposal contractual mechanisms allowing to change commitments should unforeseen circumstances arise. However, admissibility of such changes should be limited and judicially controlled.