What is SIM swapping? How to protect yourself from SIM fraud
Smartphones have become an essential part of daily life, used for everything from entertainment and communication to banking and data storage. Losing access to your phone can be a nightmare, but with SIM swapping, cybercriminals don’t need to steal your physical device to take control of your accounts.
SIM swapping, also known as SIM hijacking or SIM fraud, is a cyberattack where a hacker gains access to your phone number by transferring it to a new SIM card under their control. Once they have control, they can intercept two-factor authentication (2FA) codes, access personal data, and take over online accounts. Read on to understand how SIM swapping works, the risks involved, and how you can protect yourself from becoming a victim.
How SIM swapping works
A SIM swap attack occurs when a fraudster impersonates you and contacts your mobile provider, requesting to transfer your phone number to a new SIM card. They may claim that your old SIM card was lost, stolen, or damaged. If successful, your number is deactivated from your original SIM and assigned to the attacker’s device. This affects the victim's mobile device by disrupting its connection to the mobile network, leading to loss of service and potential unauthorized access to accounts.
Many mobile carriers have verification processes in place, but fraudsters can bypass these measures by using personal information stolen through various means:
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Phishing attacks: Cybercriminals trick individuals into revealing sensitive information through fake emails, texts, or phone calls.
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Data breaches: Leaked personal data such as names, addresses, and Social Security numbers make it easier for hackers to impersonate you.
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Social engineering: Fraudsters manipulate customer service representatives into believing they are the real account holder.
If the mobile carrier is convinced, they transfer the victim’s phone number to a new SIM card controlled by the attacker. The subscriber identity module (SIM) plays a crucial role in this process by authenticating the user's identity and enabling the mobile device to connect to the mobile network.
Once they gain control over your phone number, they can reset passwords for accounts linked to your mobile number, including banking, email, and social media accounts. This gives them full access to your personal information and can lead to financial loss, identity theft, and even complete digital takeover.
Want a clearer understanding of the key terms in this article? Discover more about phishing attacks, learn how data breaches compromise sensitive information and lead to identity theft, and explore the tactics behind social engineering.
Signs that you’ve been a victim of SIM swapping
If you experience certain issues, you may be a victim of a SIM swap attack: Cybercriminals may fraudulently transfer your victim's phone number to gain control of your SIM card, allowing them to intercept calls and messages intended for you.
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Loss of mobile service: Your phone suddenly stops receiving calls, texts, or data service.
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Unusual account activity: You receive emails about password resets or login attempts from unfamiliar locations.
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Account lockouts: Your passwords no longer work, or you are completely locked out of your online accounts.
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Unauthorized transactions: Suspicious activity in your bank or financial accounts.
If you notice any of these warning signs, it is crucial to act quickly to minimize the damage.
Security risks associated with SIM swap fraud
The consequences of SIM swapping can be severe. SIM swap fraud can lead to unauthorized access to online accounts, allowing scammers to manipulate and steal sensitive data like bank details and passwords. Cybercriminals can:
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Take over your social media accounts: They can post on your behalf or use your account for scams.
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Access your email: Once inside, they can reset passwords for other accounts and gain further control.
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Drain your bank account: Many financial services use SMS for account recovery, making your funds vulnerable.
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Commit identity theft: Hackers can use your personal details to open fraudulent accounts in your name.
This gives them full access to your personal information and can lead to financial loss, identity theft, and even complete digital takeover. The broader implications of sim swap fraud include compromising personal security and enabling identity theft on a large scale.
The combination of these risks makes SIM swapping a particularly dangerous form of cybercrime.
How to prevent SIM swapping with two factor authentication
While it may be challenging to completely prevent SIM swapping, there are several security measures you can take to reduce your risk: SIM swap protection involves taking steps to safeguard your personal information and prevent SIM swap scams.
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Secure your SIM card with a PIN: Set a unique PIN code for your SIM card to prevent unauthorized transfers. Avoid using easily guessable numbers such as your birth year or postal code.
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Limit personal information online: Reduce the amount of information you share on social media, as hackers can use these details to impersonate you.
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Contact your mobile provider: Ask about additional security measures, such as account passcodes or in-person verification before making changes.
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Disable SMS-based account recovery: Instead of using SMS to reset passwords, opt for an alternative email or authentication method.
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Use a secure form of two-factor authentication: Instead of relying on SMS for 2FA, consider using authenticator apps like Google Authenticator or Authy. Security keys, which are hardware-based authentication devices, provide even stronger protection.
Additionally, being vigilant against sim swapping attacks by setting up notifications from banks and mobile carriers can serve as an early-warning system to detect and prevent unauthorized changes.
Modify online behavior
To protect yourself from SIM swapping, it’s essential to modify your online behavior. Here are some tips:
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Be cautious when sharing personal information online: Cybercriminals often gather information from social media profiles to impersonate you. Limit the amount of personal information you share publicly.
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Avoid using public computers or public Wi-Fi to access sensitive information: Public networks can be less secure, making it easier for attackers to intercept your data.
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Use strong and unique passwords for all online accounts: A password manager can help you generate and store complex passwords, reducing the risk of your accounts being compromised.
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Enable two-factor authentication (2FA) on all accounts that offer it: Instead of relying on SMS-based 2FA, use an authentication app like Google Authenticator or Authy for added security.
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Monitor your online accounts regularly for suspicious activity: Regularly check your account settings and activity logs for any unauthorized changes or login attempts.
By implementing these strategies, you can greatly lower the risk of SIM swap scams and safeguard your digital identity.
What to do if you’ve been SIM swapped by your mobile phone carrier
If you suspect you’re a victim of SIM swapping, take immediate action: Sim swap fraud scammers often engage in these activities through social media platforms, creating fake profiles to extract personal information, leveraging romance scams to gain trust, and ultimately seeking sensitive data like credit card numbers.
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Contact your mobile provider: Report the issue and request to regain control of your phone number.
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Secure your online accounts: Change your passwords and enable stronger two-factor authentication methods.
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Monitor your bank and email accounts: Look for unauthorized transactions or suspicious activity.
Report the fraud: Notify your bank, the police, and relevant authorities to take appropriate action.
Final thoughts
SIM swapping is a growing cyber threat that can have serious consequences. SIM cards play a crucial role in these attacks by identifying users and connecting phones to networks, making them a target for scammers. While mobile carriers play a significant role in preventing these attacks, individuals must also take steps to protect their digital identity. By securing your accounts, using strong authentication methods, and staying informed about cyber threats, you can reduce your risk of falling victim to SIM fraud.
Moxso offers data breach monitoring services to alert you if your personal information has been compromised. Staying proactive about cybersecurity is the best way to protect yourself from attacks like SIM swapping. Being aware of the risks and methods involved in SIM swaps is essential to mitigate the risk of falling victim to these fraudulent activities. For more cybersecurity tips, check out our guide on creating strong passwords to enhance your online protection.
This post has been updated on 25-02-2025 by Sarah Krarup.

Sarah Krarup
Sarah studies innovation and entrepreneurship with a deep interest in IT and how cybersecurity impacts businesses and individuals. She has extensive experience in copywriting and is dedicated to making cybersecurity information accessible and engaging for everyone.
View all posts by Sarah Krarup