SIM swapping, also known as SIM hijacking or phone porting fraud, is a social engineering attack where fraudsters manipulate mobile carriers into transferring a victim's phone number to a SIM card controlled by the attacker. This allows the attacker to intercept SMS-based two-factor authentication codes, reset passwords, and gain access to high-value accounts, leading to significant financial losses and reputational damage for businesses. The vulnerability of SMS-based authentication lies in its ease of exploitation, lack of physical possession requirements, and invisibility to victims until it's too late. To combat SIM swapping, it is crucial to replace SMS with stronger authentication methods like app-based authenticators, push notifications, and hardware security keys. Additionally, employing device intelligence and multi-layered authentication controls can enhance security by focusing on device recognition, behavioral analysis, and risk assessment. Encouraging users to engage with carrier-level security measures, such as setting additional PINs and enabling account alerts, can further mitigate risks. Implementing real-time risk signals, such as VPN and bot detection, can help identify suspicious activity and prevent fraud attempts, while continuous user education and monitoring of authentication patterns remain essential components in building a robust defense against SIM swapping attacks.