The Superior Court of Justice recognized the importance of standardizing the understanding regarding the validity of service of process via messaging applications, such as WhatsApp, and social media in civil actions. Given the multiplicity of decisions and the resulting legal controversy, the Court assigned Special Appeals No. 2,161,438/SP and No. 2,160,946/SP to the repetitive appeals procedure, giving rise to Repetitive Theme No. 1,345.

Currently, the Code of Civil Procedure allows for service of process via electronic means; however, it establishes that this will be carried out through the electronic addresses indicated by the defendant in the Judiciary's database. Nevertheless, procedural law does not directly regulate the use of instant messaging applications or social networks as a formal means of service of process, which has generated divergent interpretations in case law.

In accordance with the referral, the Special Court, under the rapporteurship of Minister Sebastião Reis Júnior, established that the main legal question is to define whether service of process via messaging applications or social networks is valid in civil actions, with the aim of consolidating a uniform understanding throughout the country. The decision to refer the matter to the repetitive procedure was taken by majority vote, reflecting the existence of multiple individual decisions on the subject and the need for legal certainty.

This is because, in specific cases, state courts have resisted the adoption of service of process via messaging applications, demanding strict adherence to Article 246 of the Code of Civil Procedure, with prior registration of the recipient's email address in the Judiciary's databases, arguing that the importance of the service of process requires more traditional and secure means. On the other hand, there are precedents in the Chambers of the Superior Court of Justice that admit the validity of service of process via application, provided it is demonstrated that the purpose of the act was effectively achieved, with identification of the recipient and unequivocal knowledge of the communication, in light of the principle of procedural economy, which highlights the jurisprudential divergence and the complexity of the matter.

The judgment on Case 1345 should, therefore, define clear parameters and minimum criteria for the eventual use of messaging applications and social networks as instruments of service of process in civil actions. It will be up to the Superior Court of Justice (STJ) to assess whether this form of procedural communication is compatible with the principles of due process, adversarial proceedings, full defense, and legal certainty. Under the repetitive appeals procedure, the expectation is that the legal thesis will be established within one year of the referral, that is, in this case, by May 2026. The thesis to be established will have a significant impact on forensic practice and the routine of the Judiciary, directly influencing the modernization of procedural acts and guiding judges, lawyers, and courts regarding the validity or not of service of process by digital means in Brazilian civil procedure.