Title Third: Unjust Enrichment

Article 140

Article 140: Whoever has enriched himself at the expense of another without just cause is liable to restitution.

Article 141

Art. 141 - The obligation of the enriched party towards the enricher exists, in this form and by virtue of this source, only if the following conditions are met: 1 - An enrichment, whether direct or indirect, pecuniary or moral, must have been realized by the alleged enriched party. 2 - A corresponding impoverishment must have been suffered by the enricher, due to the transfer of a property or value made by them or a service rendered by them; 3 - The realized enrichment and the corresponding impoverishment must be devoid of a legal cause that would justify them; 4 - The enricher must not have at their disposal, to obtain satisfaction, any other action than the one based on enrichment, which has, in relation to all other legal means, a subsidiary character.

Article 142

Art. 142 - Restitution is only due by the enriched party up to the amount of the enrichment that still exists in their favor on the day of the claim, unless otherwise provided for by law. However, this is not the case if the enriched party was in bad faith at the time of the enrichment, in which case they remain accountable for the entirety, regardless of any subsequent events - loss, alienation, or deterioration - that may occur; in this case, they bear the risks and must return all the fruits received or that they should have received, and can only claim reimbursement for necessary expenses.

Article 143

Article 143: Whoever, mistakenly believing himself to be a debtor, has paid due to an error of law or fact what he did not owe, has the right to act in restitution against the enriched party.

Article 144

Art. 144 - There is no grounds for restitution: 1 - If the obligation, which existed civilly, was subject to a term that had not yet fallen due, and even if the debtor believed it to be due; the payment of interest cannot be claimed by him for the intermediate period; 2 - If the obligation was natural or purely moral, at least as long as the person who performed the service was aware of the exact situation at the time it was performed; 3 - If the enriched party, who was in good faith at the time of the transaction, has destroyed or cancelled their title, has waived the guarantees of the claim or has allowed the prescription to be completed in favour of their true debtor.

Article 145

Article 145 - There is a need for reiteration: 1 - If the obligation was subject to a suspensive condition unknown to the debtor and not fulfilled; 2 - If the debtor had, to repel the creditor's action, an absolute exception of which he was unaware; 3 - If he believed himself civilly bound when the obligation incumbent upon him was purely moral or even natural.

Article 146

Article 146 - The principles established for illegitimate enrichment in general are applicable to the payment of indemnity.