Mercosur: signing across the border.
Mutual recognition of documents and signatures among the bloc's countries.
A Uruguayan company signs a contract with a Paraguayan supplier. A Brazilian student submits in Montevideo a degree digitally signed in Brazil. An Argentine customs broker receives a certificate of origin issued in Brazil. In every case, the same question arises: is a signature made there valid here? Within a regional bloc with intense trade, the answer cannot depend on the goodwill of each individual office.
The problem of borders
Each Mercosur country has its own signature law, its own root certification authority and its own accredited providers. Within each country, the chain of trust is clear. But a Uruguayan validator does not, by default, recognize the Brazilian root, and vice versa. Without an agreement, a signature that is high level in its country of origin may be treated next door as a simple signature, or simply as unknown.
Two legal pieces
The principle: Resolution 37 of 2006
In July 2006, the Common Market Group approved Resolution 37/06 on the recognition of the legal effect of electronic documents, electronic signatures and advanced electronic signatures within Mercosur. It sets the conceptual foundation: an electronic document satisfies the requirement of written form, and an advanced electronic signature can have the same value as a handwritten one, within the framework of mutual recognition agreements. The resolution does not create a regional authority: accreditation of providers remains national.
The mechanism: the 2019 mutual recognition agreement
In December 2019, in Bento Gonçalves, Brazil, the countries of the bloc signed the Mercosur Agreement on Mutual Recognition of Digital Signature Certificates. Its aim is for certificates issued by accredited providers in one country to have the same effects in the others as in their country of origin. Each country must approve it domestically; Uruguay did so through Law 19,918 of 2020.
From agreement to practice
Signing an agreement is only the start. For a validator to genuinely recognize a foreign signature, countries have to exchange technical information: which roots and providers are authorized, under what policies, and how their revocation status can be checked. That is why implementation is moving forward bilaterally. According to Uruguay's Electronic Certification Unit (UCE), recognition with Paraguay has been in effect since June 2023 and with Brazil since April 2024, while a technical implementation memorandum was signed with Argentina in 2022.
- Political and legal agreement. The countries commit to recognizing one another.
- Domestic approval. Each parliament or government incorporates it into its law.
- Technical implementation. Roots, policies and status checking services are exchanged.
- Updated validators. Tools add the other country's trust anchors.
Beyond signatures: identity
The next step is to recognize digital identities as well. The Mercosur Digital Citizen initiative, launched in 2024 with support from the Inter American Development Bank (IDB) and the Latin American and Caribbean e Government Network (Red GEALC), seeks to let citizens use their national digital identity to complete procedures in another country of the bloc. It explicitly takes the European model as a reference and began between Brazil and Uruguay with a limited set of procedures.
Mercosur built signature recognition in two steps: a principle, Resolution 37/06, and a mechanism, the 2019 mutual recognition agreement. Implementation is bilateral and technical, and includes the exchange of trust anchors. The next horizon is recognizing digital identities across countries as well.