The article discusses the importance of keeping the same phone number for multi-factor authentication (MFA) purposes, according to cybersecurity expert Rachel Tobac. MFA is a crucial security measure that adds an extra layer of protection by requiring a second form of authentication, often a code sent to a user’s phone. Tobac warns that changing phone numbers can create security vulnerabilities, as accounts may still be linked to the old number, allowing potential attackers to bypass MFA. She recommends keeping the same phone number for as long as possible, even when switching carriers or plans. The article also highlights the risks of SIM-swapping attacks, where attackers trick carriers into transferring a victim’s phone number to a new SIM card they control. Tobac advises enabling additional security measures like app-based authenticators or physical security keys to mitigate these risks.