Summary
- Anatel’s Board of Directors maintained mandatory call authentication for large callers as of 11/15, rejecting requests from TIM and sector entities.
- The measure aims to increase security and combat fraud, reaching around 350 companies that make more than 500,000 calls per month.
- Call authentication verifies the legitimacy of the originating number, combating practices such as spoofing.
The Board of Directors of the National Telecommunications Agency (Anatel) decided, this Tuesday (04/11), to maintain the implementation of mandatory authentication of calls generated by so-called large callers, those who make more than 500 thousand calls per month. The measure comes into force on November 15th and aims to increase security and combat telephone fraud.
The decision, taken in Brasília, rejected petitions from the operator TIM, the Brazilian Association of Competitive Telecommunications Service Providers (Telcomp) and the National Union of Telephone Companies (Conexis Brasil Digital). The entities sought to change the measure, established by ruling number 201, of August 14th.
The rejected petitions requested three main changes:
- Changing the deadline, currently set for November 15
- The removal of cell phone operators from the obligation to authenticate
- Returning code 0303 as an alternative to authentication
The rapporteur’s analysis
Councilor Edson Holanda, rapporteur on the matter, presented a technical analysis refuting the three requests, and his proposal was unanimously approved by the Board of Directors. The advisor highlighted that 90 days (between August and November 15) are sufficient and argued that the universe of subscribers affected by the rule is small – around 350 companies. Furthermore, Holanda pointed out that the authentication solution is technically ready to be made available.


Regarding the request to exclude mobile operators from the obligation, the rapporteur noted that the implementation stage of the solution in these networks is already advanced and that the exclusion would create a vulnerability.
Holland still considered the idea of 0303’s return to be inappropriate. He explained that authentication guarantees the identity of the caller, while a generic prefix does not offer the same security against changing the originating number.
At the end of the analysis, the counselor highlighted that the agency will maintain constant monitoring of caller behavior and may promote changes to the rules, if necessary, to protect the population against abusive practices.
What is call authentication?


Call authentication is a set of technical mechanisms implemented in telephone networks to verify that the number making a call is, in fact, who it says it is. The main objective is to combat spoofing, a fraudulent practice in which criminals or authors of abusive calls mask the originating number. In this fraud, the user may receive a call that appears to be from their bank, an authority or a known contact, when, in fact, it is a scammer.
With authentication, the originating operator digitally signs the call, certifying its legitimacy. The operator receiving the call, in turn, verifies this signature before completing the call to the consumer, allowing fraudulent calls to be blocked before they reach their destination.
Anatel’s measure focuses especially on telemarketing or billing companies, which generate a massive volume of calls. Authentication ensures that these companies cannot falsify their origin numbers.
Source: https://tecnoblog.net/noticias/anatel-mantem-data-para-autenticacao-obrigatoria-de-chamadas-no-brasil/
