Contracts for works, goods, or services, including consultancy agreements signed by private individuals with contracting entities, fall under the purview of the Organic Law of the National Public Procurement System and its accompanying Regulations. The Regulations underwent substantial modifications in February 2023, introducing key changes, such as a substantial change in the imposition and collection of fines for non-compliance with contractual clauses. The primary objective of this article is to delineate the background of penalty enforcement within the law and to compare the associated procedures between the 2009 Regulations and the revised Regulations after the February 2023 reform. This analysis is conducted with a focus on the principles of due process that underpin the rule of law, serving the interests of both natural persons and legal entities. The methodology adopted for this study is the abstract-concrete approach, which concentrates attention on specific facets of the subject matter through abstraction, enabling a clear differentiation between the unique and secondary aspects. The findings reveal that the Organic Law of the National Public Procurement System, in Article 71, mandates the inclusion of penalty clauses in cases of non-compliance with project deadlines and specifications. The reformed Regulations, associated with the Organic Law, have instituted a comprehensive procedure for the collection of penalties, with provisions for potential appeals at the administrative or judicial levels. The study yields several conclusions, notably the acknowledgment that the State, through the regulatory reform, upholds the principles of due process, thereby enhancing legal certainty for contractors.