Marlene Baiton
Fact-checked by Sam Boyd
We tend to think of hackers as tech-savvy criminals cracking complex codes. But in reality, many cyberattacks require very little technical skill. Instead, cybercriminals rely on deception and stolen personal data to raid your accounts and ruin your life.
SIM swapping is one of the most dangerous tactics hackers use. This attack lets hackers hijack your phone number — which is linked to all your accounts — giving them direct access to your most sensitive information.
In this guide, I’ll explain how SIM swapping works and the warning signs indicating it’s happened. I’ll also go over the best practices for protecting yourself from this devious attack, including using a good antivirus app, such as Norton, to protect yourself from phishing scams and malware.
What Is SIM Swapping?
SIM swapping is a form of identity fraud where hackers hijack your phone number by transferring it to a SIM card they control. It’s essentially a skeleton key to your digital life — they can intercept calls and text messages, including security codes used for two-factor authentication (2FA). Hackers can also reset your email, bank accounts, and social media passwords by requesting SMS-based verification codes. In some cases, they can even bypass account recovery protections. Once inside, they can lock you out of your account, steal money, and commit identity theft, including opening credit lines in your name.
How Does SIM Swapping Work?
It all starts with the hackers gathering personal details about their victims. They obtain this information through phishing scams, data breaches, or dark web leaks. They look for key information such as your name, address, phone number, and answers to security questions — anything that helps them impersonate you.
Next, the hacker contacts your mobile phone carrier, pretending to be you and requesting a SIM card replacement. They often claim their phone was lost or damaged to make the request seem urgent and legitimate. Using your stolen personal data, they’ll pressure or manipulate customer service representatives to approve the transfer.
If your mobile phone carrier doesn’t have very good security policies, the hacker can quickly gain control of your phone number. Once the switch is complete, they can intercept your calls and text messages, including one-time passcodes for two-factor authentication (2FA).
What Happens If Your SIM Card Is Swapped by a Hacker?
Once hackers snag your SIM, they’ve got a loaded gun — your phone number turns into a quiet trigger for chaos that spreads. A single swap can spiral into a full-blown assault on your finances, identity, and peace of mind — here’s how:
Banking Fraud
Hackers can reset your online banking passwords and gain full access to your accounts. They’ll transfer funds, make unauthorized purchases, or even apply for loans in your name. If they move money to cryptocurrency wallets, recovering your stolen funds can be virtually impossible.
Even if your bank detects suspicious activity, you might struggle to regain access to your account quickly. Without control of your phone number, you won’t be able to verify your identity, which means delayed fraud investigations and mounting financial losses.
Real-World Example: In a U.S. Department of Justice case, a SIM-swapping ring targeted over 50 Americans, stealing $400 million in cryptocurrency. One victim saw their life savings — $150,000 — wiped out in hours after attackers used stolen data and fake IDs for a SIM swap that hijacked their number from a major carrier.
Identity Theft
Hackers can impersonate you and open new accounts in your name. With access to your data, criminals can apply for credit cards, loans, and other financial services using your identity (similar to banking fraud). They can also use your phone number to bypass verification processes, making it easier to carry out fraudulent activities without raising suspicion.
Identity theft can severely damage your credit score and take years to resolve fully. Victims often spend months disputing fraudulent charges, closing unauthorized accounts, and restoring their financial reputation.
Social Media & Email Hijacking
Attackers can lock you out of your accounts by resetting your passwords using SMS-based two-factor authentication (2FA) codes. Once inside, they can change your recovery settings, making it nearly impossible to regain access. Hackers often use hijacked accounts to scam your contacts, spread malware, or demand ransom in exchange for returning control.
This kind of attack can have serious financial and reputational consequences. Losing a social media presence or a business email account could mean lost revenue, damaged relationships, and a long recovery process.
Data Breaches
Hackers can breach your email, cloud storage, or messaging apps — unlocking access to your photos, sensitive documents, and private conversations. They can use this information for blackmail, sell it on the dark web, or exploit it for further fraud.
Even if you secure your accounts later, the damage will already be done. Once personal data is exposed online, removing it is nearly impossible, and you could face ongoing privacy risks for years.
Reputational Damage
Hackers can impersonate you to ruin your credibility. They can send harmful messages, post offensive content, or pose as you in ways that damage your personal and professional relationships. If they control a business account, they can spread false information, causing trust issues with customers and colleagues.
Rebuilding your reputation after a cyberattack can be difficult. Even after regaining access, you might have to issue public statements, apologize for the hacker’s actions, and repair the trust of those affected.
Locked-Out Phone Service
Once your number is transferred, your phone’s SIM card becomes useless. You won’t be able to receive calls or texts, including essential notifications from banks, work, or medical services. This can create serious problems, especially if you need urgent access to critical accounts.
In emergencies, losing access to your phone service will put you at significant risk. Without the ability to call for help, contact loved ones, or receive medical alerts, the impact of a SIM swap attack can extend beyond just financial and personal reputation losses.
Signs of a SIM Swap Attack
A SIM swap attack can happen without warning — but there are key signs that indicate something is wrong. Watch for these:
- No signal without reason. Your SIM may have been deactivated if you can’t make calls, send texts, or use mobile data. Restart your device to rule out a network issue, and check downdetector.com on another device to see if your carrier is down.
- Unexpected SIM-related messages. Receiving emails or text messages about a SIM card change that you didn’t authorize is a clear sign of trouble. Some carriers send alerts before processing a request, giving you a small window to stop an attack.
- Inability to log into accounts. A hacker may have taken over if you suddenly can’t access your email, bank, or social media accounts due to incorrect passwords. Many services reset via SMS, letting criminals lock you out once they’ve got your number.
- Unusual activity on accounts. If you receive notifications about login attempts, password changes, or new devices accessing your accounts, take immediate action. Even if you still have control of your phone, these alerts could mean an attacker is at work.
- Unexpected 2FA prompts. Random texts or emails with 2FA codes you didn’t request could signal a hacker’s trying to break in.
- Strange calls or texts from your contacts. Friends or family reaching out about odd messages from your number could indicate that a hacker is impersonating you.
Pro Tip: If you notice any warning signs, contact your mobile carrier immediately and check for unauthorized activity on your accounts. The faster you respond, the better your chances of minimizing the damage.
What to Do If You Believe You’re a Victim of SIM Swapping
Acting quickly is crucial to limit the damage and regain control of your accounts. Here’s a step-by-step guide to help you take action:
- Contact your mobile carrier. Immediately inform your mobile carrier about the SIM swap incident. Use a landline or a friend’s phone if necessary, as your mobile number may be compromised. Request that they investigate the incident and restore your account to your control.
- Contact your bank and financial institutions. Notify your bank and other financial organizations about the incident, especially if you suspect unauthorized transactions. Review your accounts for any unusual activity and ask them to freeze or secure your accounts temporarily to prevent further damage.
- Use identity theft protection. If you’ve already signed up for an identity theft protection service like Norton’s LifeLock, contact them now — their support can guide you through the mess, helping you flag fraud with credit bureaus or tackle identity theft fallout. If not, continue with the following steps to limit damage. Note: Norton Lifelock’s features are region-specific.
- Place a fraud alert with the credit bureaus. Contact Equifax, Experian, or TransUnion (or your country’s equivalent) to flag your credit file, prompting lenders to verify your identity before approving credit in your name.
- Monitor your credit reports. Regularly check your credit reports to catch any suspicious activity. You can access your reports and look for signs of identity theft or unauthorized credit inquiries.
- Report the incident. Report the SIM swap to the Federal Trade Commission (FTC) at identitytheft.gov and the FBI’s Internet Crime Complaint Center (IC3) at www.ic3.gov. These agencies can guide you through the following steps and help you file a report for further investigation.
- Keep a detailed log. As you work through the recovery process, log all your actions. Record who you contacted, when, and the steps they promised to take. This documentation will be useful if you need to resolve any disputes or follow up with service providers later.
- Change all your passwords. Secure your accounts by changing the passwords to your email, bank accounts, social media, and any other services that use your phone number for authentication. A password manager like 1Password can help you create strong, unique passwords fast — locking everything down tight to stop further breaches.
How to Protect Yourself From SIM Swapping
Hackers need access to your personal information to pull off a SIM swap — so don’t give them an easy way to obtain it. Here’s how to protect yourself from SIM swapping:
Don’t Share Any Personal Information
Avoid posting sensitive information online, such as your phone number, birth date, or the answers to your security questions. This information is often used to authenticate accounts and can make you an easy target for SIM swapping.
Keep your social media accounts private, and think twice before revealing personal details in public forums, even if the request seems harmless. Almost anybody who tries hard can see everything you do or share online.
Use App-Based Authentication
SMS-based two-factor authentication (2FA) can be intercepted during a SIM swap attack. Instead, use an authentication app like Microsoft Authenticator or Aegis that generates codes on your phone. Tools like RoboForm take it further, auto-filling 2FA codes alongside passwords.
For an even higher level of security, consider using biometric 2FA. Enable facial recognition or fingerprint scans as an extra layer of protection for your most critical accounts.
Set Up a Number Transfer PIN With Your Mobile Carrier
Many mobile carriers offer a Number Transfer PIN to prevent unauthorized SIM swaps. When enabled, this PIN is required for any request to transfer or change your SIM card.
Even if a hacker gains access to your personal information, they won’t be able to complete a SIM swap without this PIN. Contact your carrier to ensure this feature is activated on your account, adding a crucial barrier to SIM swap attacks.
Watch for Phishing Attempts
Be vigilant — treat virtually any request for personal information as a scam unless you’re 100% certain the source is legitimate. For instance, your bank and mobile carrier will never ask for sensitive data via email or text.
If you do receive a suspicious message, don’t click any links. Generally, it’s best not to click email links unless you expect one from a trusted source. Instead, report these fraudulent phishing scams directly to your service provider and contact your local phishing reporting service (a quick Google search will let you know who to contact in your area).
Use a Good Antivirus App
An antivirus app can help protect you from phishing scams and other online threats. It can detect malicious websites and links before you click, blocking access to potential fraud sites.
Antivirus apps can also scan for malware that could compromise your devices and personal information — and some even alert you if your data appears on the dark web. Norton excels in these areas, but it’s certainly not the only good antivirus in 2025.
Monitor Account Activity
Enable alerts for any unusual activity on your financial accounts, such as changes to login information, login attempts from unrecognized devices, or changes to your contact details. Many banks and mobile carriers provide these alerts free of charge.
By monitoring your accounts, you can quickly spot any unauthorized changes and take immediate action to minimize the damage. If you notice anything suspicious, contact the respective organization immediately.
Keep Passwords Unique
Reusing passwords across different services makes it easy for hackers to access all your accounts with that password. An easy-to-use password manager (like NordPass, for example) is the best way to create and store unique, complex passwords for each account.
This way, even if one of your accounts is compromised, others will remain secure. Additionally, avoid using easily guessable passwords like your name, birth date, or sequential numbers like “123456”.
Limit Where You Use Your Phone Number
Many services use phone numbers for two-factor authentication, but your phone number is also one of the easiest targets for SIM-swapping attacks. Use email or authentication apps instead of linking your phone number to critical accounts like banking, email, and social media where possible.
The less your phone number is tied to your essential services, the harder it is for hackers to exploit. And if you sign up for a service where your phone number is optional, it’s best to simply not provide your number at all.
Frequently Asked Questions
How does SIM swapping work?
SIM swapping is a scam where hackers impersonate you to take control of your phone number. They gather personal information before contacting your mobile carrier — pretending to be you — and requesting a SIM card swap.
The attacker can then use this access to hijack your accounts, commit fraud, and steal your identity. They often target sensitive accounts like banking or email.
How do you know if your SIM was swapped?
There are many signs of a SIM swap attack. They include losing access to your phone’s cellular service, such as being unable to make calls, send texts, or use mobile data. You might also receive unexpected messages about changes to your SIM card or be unable to log into accounts that rely on SMS-based authentication.
If you notice unusual activity on your accounts, such as password resets or unauthorized logins, it could be a sign that a hacker is taking over. Contact your mobile carrier immediately if you suspect a SIM swap to stop the attack.
Can you stop SIM swapping?
While it’s impossible to eliminate the risk, you can take several steps to protect yourself from SIM swapping. First, contact your mobile carrier to set up a number transfer PIN or a security PIN to prevent unauthorized SIM swaps.
Additionally, avoid sharing sensitive personal information online, and use app-based authentication rather than SMS-based two-factor authentication (2FA). You should also regularly monitor your accounts for unusual activity and be cautious of phishing attempts.
What is the risk of SIM swapping?
The risks of SIM swapping can be severe, including financial fraud, identity theft, and unauthorized access to your personal accounts. Hackers can steal money from your bank accounts by intercepting two-factor authentication codes, make fraudulent transactions, or apply for loans in your name.
They may also hijack your email, social media, and other critical accounts, causing reputational damage or using your identity for further fraudulent activities. Additionally, losing access to your phone service during an attack can prevent you from receiving important notifications or contacting emergency services.
