The modification of a contract is an area presenting a real interest for the practitioners in the field. More and more, the contractors tend to resolve their implementation problems through addendums which, most often, don’t respect the publicity conditions imposed by the national and European legislation. OUG nr. 34 and HG nr. 925 don’t have provisions regarding contract modifications, the principles being imposed by the European case-law. In present, the single act with a chapter on contract modification is Ordin nr. 543/2013. The real conflict is knowing when a modification can be qualified as substantial or not and which are the elements to be takeni into consideration during the evaluation process. The new Directive 2014/24/CE r...