The extension of the period to register mobile telephone lines provides a new opportunity for users to regularize their situation and avoid problems related to the reassignment of numbers, a common practice in telecommunications that can affect access to digital accounts.
According to the cybersecurity firm ESET, the main risk is not in the linking process, but when a user stops using a number that is still associated with banking services, emails, social networks or messaging applications.
Why is it important to register the number?
The Telecommunications Regulatory Commission (CRT) reports 63 million linked mobile lines, of which 40.2 million are prepaid and 22.8 million postpaid.
David González, computer security researcher at ESET, pointed out that mandatory registration does not represent a direct danger. “The real focus is on the possible reassignment of a number to another person, a common practice that can have implications if the number remains associated with digital accounts of the previous owner,” he explained.
Number reuse allows operators to optimize numbering resources. When a line is inactive for a certain amount of time, it can be recovered and assigned to a new user. That new owner could receive messages, verification codes or calls directed to the previous owner. Although it does not grant automatic access to accounts, it can cause difficulties in recovering access or updating data.
Recommendations to protect your accounts
“The scenario can lead to calls, messages and notifications addressed to the previous owner, exposing users and companies to operational risks,” González said.
ESET recommends keeping the line active, updating contact information when changing numbers and periodically reviewing which accounts are still linked to the cell phone. It also suggests using multi-factor authentication with specialized apps to reduce reliance on SMS messages as the sole verification mechanism.




