The unjust enrichment of the administration stands as a legal title of imputation of state damage, in accordance with the liability regime enshrined in Article 90 of the Political Constitution of Colombia. However, this work will address the issue of unjustified enrichment from its status as a general principle of law and autonomous source of obligations, highlighting the loss of autonomy of the actio in rem verso in the contentious administrative jurisdiction, and its subsumption in the means of control of direct reparation and contractual disputes.