Court of Monza, judgment of 15 July 2026, No. 1486

Contractual expert determination (perizia contrattuale) is an institution akin to but distinct from arbitration and from arbitraggio (third-party determination of the content of a contract): by it the parties entrust to one or more third parties, chosen for their technical expertise, the task of making a technical appraisal or assessment, its features being the contractual nature of the expert-arbitrator's activity and the binding effect of the determination, which the parties undertake to accept as the direct expression of their own will.
Contractual expert determination differs from arbitraggio in that the third party does not act according to fair appraisal or mere discretion, but must conform exclusively to the technical and scientific rules of his own field of competence.
The system of challenges against the determination of the expert-arbitrator is derived exclusively from the general rules on the invalidity of legal transactions, so that a contractual expert determination may be challenged only for the defects capable of vitiating any expression of contractual will, such as mistake, duress, fraud and incapacity of the parties, and not on grounds concerning the mere erroneousness of the quantification.