SIM swap fraud is an account takeover scam that targets a weakness in some forms of two-factor authentication in which a call or text message sent to a mobile telephone is the second factor or step. Also known as port-out scam, digital SIM swap, SIM splitting, and simjacking, the SIM swap scam exploits the ability of subscriber identity module (SIM) cards to be ported seamlessly by mobile phone service providers from device to device bearing different telephone numbers. Typically, carriers use this feature when customers buy new phones, switch service, lose their device, or experience theft.