SIM swap scam

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A SIM swap scam (also known as port-out scam or SIM splitting[1]) is a type of account takeover fraud that generally targets a weakness in two-factor authentication and two-step verification in which the second factor or step is a text message (SMS) or call placed to a mobile telephone.

How the fraud works[edit]

The fraud centres around exploiting a mobile phone service provider’s ability to seamlessly port a telephone number to a device containing a different subscriber identity module (SIM). This feature is normally used when a customer has lost or had their phone stolen, or is switching service to a new phone.

The scam begins with a fraudster gathering personal details about the victim, either by use of phishing emails, by buying them from organised criminals,[2] or by directly socially engineering the victim.[3]

Once the fraudster has obtained these details, they then contact the victim's mobile telephone provider. The fraudster uses social engineering techniques to convince the telephone company to port the victim's phone number to the fraudster's SIM. This is done, for example, by impersonating the victim using personal details to appear authentic and claiming that they have lost their phone. In some countries, notably India and Nigeria, the fraudster will have to convince the victim to approve the SIM swap by pressing 1.[4][5][3]

Once this happens the victim's phone will lose connection to the network and the fraudster will receive all the SMS and voice calls intended for the victim. This allows the fraudster to intercept any one-time passwords sent via text or telephone calls sent to the victim, and thus to circumvent any security features of accounts (be they bank accounts, social media accounts, etc.) that rely on text messages or telephone calls.


A number of high-profile hacks have occurred utilizing SIM swapping, including some on the social media sites Instagram and Twitter. In 2019, Twitter CEO Jack Dorsey's twitter account was hacked via this method.[6][7]


  1. ^ admin (2014-05-09). "Alert – how you can be scammed by a method called SIM Splitting". Action Fraud. Retrieved 2018-08-22.
  2. ^ Tims, Anna (2015-09-26). "'Sim swap' gives fraudsters access-all-areas via your mobile phone". the Guardian. Retrieved 2018-08-22.
  3. ^ a b "Many Bengalureans lose cash to sim card swap fraud - Times of India". The Times of India. Retrieved 2018-08-22.
  4. ^ "Experts Finger Insiders in Telcos for Rising SIM Swap Fraud – Nigerian CommunicationWeek". Retrieved 2018-08-22.
  5. ^ "You will be requested to press 1 or authenticate this Swap | Gadgets Now". Gadget Now. Retrieved 2018-08-22.
  6. ^ "How to Protect Your Phone Against a SIM Swap Attack".
  7. ^ Brandom, Russell (August 31, 2019). "The frighteningly simple technique that hijacked Jack Dorsey's Twitter account". The Verge.

External links[edit]