I. The relationship between the concepts of document and data
El derecho continental ha construido su sistema de seguridad jurídica preventiva en torno al documento público, que es el soporte o continente, ya sea analógico o digital, de un conjunto de datos cualificados.
In the notarial context, data can be defined as the unit of information capable of being identified, parameterized, transmitted, interoperated, reusable and capable of producing legal effects because it comes from a reliable source having been subjected to a verification process by the notary when exercising legality control.
This definition is aligned with the concept of data in article 2.1 of Regulation (EU) 2023/2854, of December 13, 2023 (Data Act) as “any digital representation of acts, facts or information (…)”, and also with that of interoperability in article 2.40 as “the ability of two or more (…) systems (…) to exchange and use data in order to perform their functions.” functions.”
Although this definition is thinking about the digital field, the truth is that the proposed concept is neutral with respect to the document medium, since it is possible to extract the most relevant data from an analog document and transfer it to the digital field.
As can be seen, the relationship between document (container) and data (content) constitutes one of the key points in the new digital paradigm: the greater the need for interoperability, the greater the risk of loss of quality if there is no assurance that the data is reliable. This problem is aggravated in the legal field, where the data is not neutral, but rather produces effects on traffic. Incorrect or decontextualized data can generate negative legal consequences on rights, obligations and consolidated legal situations.
II. The European construction of digital trust
Therefore, data quality cannot be conceived solely as a technical issue, but as a legal problem, and this is reflected in the evolution of Community Law in matters of electronic identification and company law.
II.1. Electronic identification
In terms of electronic identification, Regulation (EU) 910/2014, of July 23, 2014 (eIDAS), arose precisely by admitting that the lack of trust is the main obstacle to the development of the digital market. Specifically, Considering 1 confirms that the problem is not only technological, but also one of legal uncertainty. It is not the absence of tools, but the absence of confidence in the veracity of the information obtained using them.
This raises a fundamental question: Who guarantees the veracity of information in the European digital ecosystem? This question is answered by Regulation (EU) 2024/1183, of April 11, 2024 (eIDAS 2), which represents a decisive conceptual change, by introducing the concepts of attribute (attribute) and authentic source (authentic source), which in turn will be the bases of the European digital identity portfolios. (European Digital Identity Wallets).
Concretamente, define fuente auténtica en el artículo 3.47, como el “(…) sistema mantenido bajo la responsabilidad de un organismo del sector público (…) que se considera una fuente principal de dicha información, o que está reconocido como auténtico (…)”. Esta definición encierra una idea de gran alcance: la confianza en el atributo no deriva de su formato ni de su tecnología, sino de su origen institucional.
II.2. Derecho societario
En paralelo, la evolución del Derecho societario europeo refuerza esta misma idea: en 2019 la Unión Europea aprobó la Directiva (UE) 2019/1151, de digitalización de sociedades. Seis años más tarde, en enero de 2025, publica su evolución natural, la Directiva (UE) 2025/25 de 19 de diciembre de 2024, tras haber identificado los problemas que genera la falta de fiabilidad y de actualización de los datos que se publican en los registros mercantiles: Europa no confía en que, por sí mismos, los registros mercantiles puedan dar datos fiables, y ha comprendido que la calidad de información de un registro no depende del registro en sí, sino de la calidad del dato consignado en el documento que accede al mismo.
Por supuesto, como ocurre en tantas otras materias, ni todos los documentos notariales europeos, ni todos los registros mercantiles europeos son iguales.
¿Qué tipo de dato persigue la Unión Europea? De los Considerandos 2, 5 y 6 resulta que el dato societario debe ser fiable*,* exacto, actualizado, y creíble. En definitiva, debe ser auténtico, lo cual solo ocurre cuando quien lo recibe y verifica, es fuente auténtica.
En este ámbito, fuente auténtica debe ser el organismo público que recibe de manera directa la información de la sociedad y los socios, la comprueba y la remite a publicación al registro mercantil. Ese organismo público podrá ser administrativo, judicial o notarial como ya se reconoció en la primera Directiva de 2019 y ahora reafirman el Considerando 9 y el artículo 10*.* Por tanto, no se cuestiona que el control preventivo de legalidad, extendido al dato, sea importante, sino que precisamente lo que se hace es reforzar ese control ex ante y, en consecuencia, mientras que en la primera Directiva digital se preveía el control preventivo, centrado sobre todo en socios fundadores, en la segunda Directiva de 2025 se exige e intensifica ese control preventivo y se extiende a otros datos societarios relevantes.
III. El notariado como paradigma de fuente auténtica
La Unión Europea, en definitiva, está construyendo un modelo en el que la confianza se deposita en el origen primario del dato o atributo, sin perjuicio de que existan mecanismos de publicidad secundaria.
In other words: what a secondary authentic source (for example, the commercial registry) publishes is reliable because the primary authentic source (a public body, in our case a notary) has verified it and incorporated it into an authentic document.
Por tanto, gracias a los documentos auténticos, los registros públicos pueden actuar como fuente auténtica, o lo que es lo mismo: si alimentamos un registro con datos no verificados, lo que publicará serán datos no verificados. Es el clásico GIGO, que parece no conocer el Anteproyecto de Ley de Integridad Pública que admite el documento privado como título inscribible de la transmisión de las participaciones sociales en el Registro Mercantil, permitiendo que que éste se alimente, y publique, datos que no han sido controlados por el notario en origen.
In this Draft, it is intended to put an end to an alleged opacity, which is not such, favoring the private document, which is the perfect instrument for those who want to hide reality, by allowing simulate transmissions, use front men or alter the ownership of a company without leaving an immediate trace, and eliminating the public document, an example of transparency, of free and impartial advice from the notary, of secure identification, of prior verification that indeed whoever sells can sell, and whoever buys can buy, of the capacity and the true will to want to carry out the sale under the conditions agreed upon.
This situation has not gone unnoticed in the reports requested by the Government in relation to the Preliminary Project, for example, the Report of the Second Section of the General Codification Commission recognizes:
Que “la admisión generalizada del documento privado con firma electrónica cualificada (…) supondrá una considerable merma de seguridad jurídica”.
That “the elimination of the legality control carried out by notaries when granting a public document may mean that the process of verifying the capacity and legitimation of the grantors is omitted.”
That, “in general, the Draft (…) deserves an unfavorable comment”, that “poses important legal risks”, and that “there would be many and serious problems of interpretation of such deficient regulations, which will cause a foreseeable and always undesirable increase in litigation”.
That “the reform as a whole can be very burdensome for all Spanish limited liability companies”, since “it will imply an extraordinary increase in cost” which will also not solve the problem it aims to tackle.
Consequently, the notary not only meets the requirements demanded by European Law to be considered an authentic source, but also constitutes, by its very configuration, the paradigm of said category, as three essential elements come together in its actions: firstly, control at origin of the data (the notary is the public official who primarily, directly and immediately receives the data); secondly, its validation (the incorporation of the data is not a mechanical act, but the result of a process of material and formal control of its veracity); thirdly, integrity and conservation (the technological system that supports the entire process must guarantee that the data is not altered, destroyed or manipulated).
III.1. Legal elements
This approach, in the legal field, is based on the very nature of the notarial function as a public function of control of legality. The jurisprudence of the Supreme Court has reiterated that the notary is not a mere writer of documents, but a public official who exercises a function of preventive legality control.
Furthermore, the notarial nature of the authentic source is based on the presumption of truthfulness and integrity that the legal system attributes to the public document in article 143 of the Notarial Regulations. As the Notary of Ibiza Javier Gonzalez Granado pointed out at the II Technology Conference of Valencia in 2025, the Notarial Regulation must be understood from the perspective of the principle of data veracity, or what is the same: that the data is truthful and of quality, as a manifestation of the principle of data ordering.
III.2. Technical elements
In this sense, it can be stated that the Spanish notarial profession has been data-oriented for more than 20 years, since the technological transformation began after the emergence of the regulations on electronic signatures in the late 90s and early 2000s: the combination of the notary electronic headquarters, the electronic protocol and the single computerized index constitutes a coherent ecosystem of legal data management that covers its entire useful life: from reception and verification, through its conservation, to its use, interoperation and advertising.
Technological Center of Notaries
The Notarial Office was equipped with a Private Notarial Network (RENO) that connects the almost 3,000 notaries, the more than 18,000 employees and the corporate bodies. Through this network, notaries maintain the Notary Electronic Headquarters which allows us to be interoperable with the rest of the notaries and corporate bodies, with citizens, companies, financial entities, and with more than 5,000 public and private entities, civil registries, Prosecutor's Office, Cadastre, etc. In addition, the Electronic Headquarters is the support of initiatives such as the Notarial Citizen Portal, the Real Estate Statistical Portal, and other portals, for Banking or Business, that are to come.
For this, the notary office decided to create a technological company, which was born in 2002 and has been called the Notariat Technology Center (CTN) since 2024. It is considered a Trusted Service Provider, which is essential for qualified electronic declarations of attributes, and obtained on January 7, 2022, renewed in 2024 and in 2026, a certificate in accordance with the High Level National Security Scheme. In addition, it actively participates in the development of the European eIDAS ecosystem, intervening as a reference in forums and initiatives such as the European Blockchain Sandbox, go.eIDAS or the WeBuild consortium.
Single Computerized Index
This technological infrastructure serves to provide a large number of services, but especially to organize our function around the data, through what we call Single Computerized Index: Notaries, of each of the 8 million notarial documents that are authorized per year, must export the most relevant data to electronic format, generating a type of file or file. Let's think that, for example, between 300 and 350 legally relevant data are extracted from a deed of sale.
The aggregate set of all these files or files, duly parameterized and structured in computer support, generates a large database**,** that has the character of a public document and that serves “the due collaboration of the notary and its corporate organization with public administrations.”
It is one of the most important data infrastructures in the country, which integrates more than 175 million documents and 30,000 million datapoints, with a size of 9 Terabytes.
The recording of this data is carried out by notaries, with the enormous time that is dedicated to it and the cost that it entails. To facilitate data extraction, a AI recording service has been created at the Valencia headquarters of the Technology Center, under which the notary, with the upload of the electronic protocol, authorizes the Technology Center to extract the data with AI and carry out up to two human verifications (expert recorder and notary).
It is important to highlight that this system has not led to a decrease in the number of human employees dedicated to indexes in the Technology Center, but quite the opposite, since by applying AI solutions the product has become scalable, hence the opening of the dedicated center in Valencia to which I previously referred, with nearly 200 employees.
This system, which involves the interaction between AI and up to two human verifications, allows to avoid or mitigate hallucinations by maintaining a rigorous quality control system, consolidating the reliability of the system and, progressively, as confidence in the results increases, reduce human intervention without compromising quality, but always maintaining that of the notary, or what is the same, a notary on the loop.
This configuration also allows maintaining the creation of the Single Index in a technological environment controlled by the notary as a corporation, which not only responds to organizational convenience, but also to legal reasons: The Regulation on AI requires that any system be fully explainable, traceable and supervised by competent humans, requirements that are very difficult to meet if the operation of the system escapes institutional control or if it occurs on opaque infrastructures, externally owned or without sufficient technical guarantees.
Prevention of Money Laundering
The processing of said data through algorithms, datamining operations, identification of patterns and risk assessment by the Centralized Body for the Prevention of Money Laundering (OCP) allows the notary, by far, to be the obligated entity that better and more efficiently collaborates to eradicate money laundering, the financing of terrorism and corruption. For this reason, the FATF made its guide public in July 2019, in which it proposes to Governments a series of measures in which it is stated that “the money laundering prevention system used by notaries in Spain represents a considerable advance for Public Authorities, which thanks to its implementation now have access to a new source of valuable information: notarial indexes (…)”.
There is no better cover letter for the single notarial index than this one. There is no greater confidence in notarial data than having allowed the Spanish authorities to detect suspicious operations in real time and having been key in multiple investigations, convincing the FATF of its practical usefulness.
The cost for the State, for companies and for citizens of this system is zero, since it has been borne entirely by Spanish notaries.
Reports to the preliminary project
By the way, if the Preliminary Project that we mentioned before is successful, this system may lose its main source of information if the notarial document is weakened. In other words: a radar that has been working optimally against corruption and money laundering for years can be turned off.
For this reason, the Report of the Fiscal Council suggests, precisely referring to the role of the Single Index and the statements of the FATF that “allowing a private document to have access to the Commercial Registry is a measure that could have undesired consequences contrary to the purposes of the APLO”, therefore “the possibility of carrying out any type of commercial legal business involving social participations through a private document and maintaining the need for a public deed should be reconsidered”.
Furthermore, Report of the General Council of the Judiciary recognizes:
That “notarial control and (…) the single Index constitutes a measure of substantial effectiveness and an example of good practice.”
That “given the limitations inherent to the exclusively documentary reality on which (the registry control) is projected and the ex post moment of the operation, (this) has a different scope and intensity than the in-person control at a notarial office.”
To say in its Second Conclusion, that the requirement that "the transfer of social shares be recorded in a public document has a long tradition in our system and has deserved a positive assessment by the FATF as it allows the record (...) in the Single Index database (...). The suppression of the requirement for a public document and its replacement with a private document (...) should be reconsidered."
Of course, all of these previous reflections regarding the danger posed in all these areas by replacing the public document for the transfer of social shares with the private document, are fully applicable to article 59 of the Proposal of March 18, 2026 for Regulation EU Inc.
IV. Conclusion
In conclusion: if the notary primarily receives the legal data, verifies it, parameterizes it, preserves it securely so that there is traceability, makes it interoperable and allows citizens and Administrations to trust it, there can be no doubt that it is the authentic source paradigm, so the data available in the electronic headquarters, in the electronic protocol and in the Single Index, must necessarily be considered as verifiable attributes in the new European digital ecosystem.
They should especially be taken into account in the European Digital Identity Wallets, both the European Digital Identity Wallet and the European Business Wallet. The integration of notarial data in these portfolios is a structural issue since many of the relevant attributes in legal transactions (marital agreements, marriages, divorces, incorporation of companies, representation, civil or commercial powers, etc.) have their origin in notarial actions, although they are later published in civil or commercial registries.
All of this results from admitting that the quality of the attribute depends directly on the quality of the source** that issues it, and if we want reliable attributes, we must maintain the authenticity of the origin of the data, maintaining notarial intervention throughout the process.
Doing without the notary as an authentic source would imply weakening the reliability of the system.
The question, therefore, is not whether the notary can issue attributes, but whether citizens and companies can afford not to do so.**