A contractual arbitration award (arbitrato irrituale), having a contractual and not jurisdictional nature, is not capable of becoming res judicata, with the consequence that questions relating to errors of calculation or assessment contained therein may be examined by the ordinary courts even outside the remedies for challenge provided for institutional arbitration awards.
In a contractual arbitration award (arbitrato irrituale) rendered ex aequo et bono, a material error committed by the arbitrators in determining the sums due between the parties may be corrected by the ordinary courts in proceedings on the merits, the preclusions arising from res judicata deriving from an institutional arbitration award not being operative.