What To Do if a Scammer Has Your Phone Number

Updated on March 31, 2025.

If a scammer has your phone number, you should lock your SIM card, secure your online accounts with strong passwords and block spam calls from your phone. With your phone number, scammers can do several things, including target you with phishing attacks, spam calls, spoofing attacks and SIM swapping. These kinds of cyber attacks can lead to your personal information being compromised and even your identity being stolen.

Continue reading to learn the steps you should take if a scammer has your phone number, how scammers can get your phone number and what they can do with it.

1. Lock your SIM card

Locking your SIM card is crucial in protecting your privacy and identity, especially when you realize a scammer could be impersonating you to commit fraud. You must lock your SIM card to avoid a scammer receiving private phone calls or text messages with authentication codes, which could grant them access to your private information and online accounts.

For iPhone users, go to Settings, Cellular and SIM PIN. Toggle SIM PIN on, and enter the default PIN. Usually, the default PIN is 1111, but check with your mobile carrier before guessing anything because three incorrect guesses can result in losing access to your phone. Then, update your PIN to a new one.

For Android users, go to Settings, Security & Privacy, More security settings and SIM card lock. Toggle this on, enter the default PIN and tap Change SIM PIN to update your PIN.

2. Secure your online accounts with strong passwords and MFA

Use strong, unique passwords to prevent a scammer from using the same password to access all your accounts. You should make sure each of your passwords consists of at least 16 characters and a combination of uppercase and lowercase letters, numbers and symbols. Creating a strong and unique password is made easier with a password generator, which is a tool that produces random and secure passwords.

In addition to using strong passwords on all your accounts, you should enable Multi-Factor Authentication (MFA), which provides extra security by requiring at least one more way to verify your identity. Enabling MFA will prevent anyone from accessing your online accounts, even if they know your username or password. Some types of MFA include a PIN, a code from an authenticator app, an answer to a security question, your fingerprint or even your geographic location. However, if a scammer has your phone number, they may try to compromise any online accounts that are linked to your phone number, so it’s important not to use SMS as a type of MFA. Instead of using SMS as your primary type of MFA, use a stronger form of MFA, such as biometrics, which could be facial recognition or your fingerprint, since a scammer cannot replicate those.

3. Block spam calls from your phone

When you block spam calls from reaching your phone, you protect yourself from falling victim to scammers. Although not every spam call leads to a scam, every scam call is unwanted and has bad intentions, aiming to trick you into revealing private information or sending money to an imposter. Unfortunately, there is no way to block all spam calls from your phone, but you can block most of them by getting a call-blocking service added to your phone plan, downloading a credible spam-filtering app and signing up for the National Do Not Call Registry.

4. Ignore one-ring phone calls

Have you ever received a call from an unknown number, but it only rings once? Scammers commonly make one-ring phone calls to trick you into calling them back. If your phone rings once and suddenly stops before you get the chance to answer, refrain from calling the number back. Scammers may use local phone numbers, but they can be from anywhere in the country or even the world, and calling them back can lead to international charges on your phone bill. As a general rule of thumb, only call back phone numbers that you recognize.

5. Never click on unknown links or attachments

If you ever receive an email or text message with an unknown link or attachment, do not click on it. These links or attachments may contain malware, which is malicious software that can be installed on your device without your knowledge and steal your private information. When a scammer has your phone number, they can send text messages with unsolicited links intended for you to click on and enter your personal information, like login credentials for online accounts. However, never click on unsolicited links or attachments because your personal information could be stolen and used to commit identity theft. 

6. Report scams to the FTC

Any scam calls that you receive should be reported to the Federal Trade Commission (FTC), which fights against fraud and all types of scams to protect your identity. Once you submit a report to the FTC, you will receive additional steps based on your unique situation and the scam. The FTC will then use the information you share to collaborate with law enforcement to investigate the scam and the scammer involved.

How do scammers get your phone number?

Here are several ways your phone number could end up in a scammer’s hands:

• The dark web: Scammers can buy your phone number on dark web forums and sites, in addition to other compromised Personally Identifiable Information (PII), to commit identity theft.
• Phishing emails: You may be tricked into sharing your phone number after responding to a fraudulent message sent by a scammer impersonating a legitimate person or business.
• People finder sites: These websites collect and publish your personal information based on public records. Scammers can find your phone number and use it to conduct scam calls.
• Stolen mail: Scammers may steal mail from your mailbox or even a dumpster to learn your phone number, wanting to use it to target you with phishing attacks.

What can scammers do with your phone number?

Because your cell phone is always on you and contains so much important information, it is a highly valuable object to thieves. However, there are many ways scammers can cause harm without having to physically steal your phone. Here are some of the most common things scammers can do with just your phone number.

SIM swapping

SIM swapping happens when a scammer tricks your mobile carrier into thinking your phone is tied to a different SIM card. They don’t even need to steal your phone to impersonate you. Once the scammer successfully swaps your SIM card, they will start receiving all your phone calls and text messages on their device. The scammer can then scam your loved ones while impersonating you or use the SIM card to bypass Multi-Factor Authentication (MFA) security for any online accounts.

Target you with phishing attacks and spam calls

Scammers will use your phone number to target you with fake text messages and bombard you with spam calls. In these calls, scammers will pretend to be tech support agents, bank representatives, owners of charities or even government agencies. They may ask you to verify your personal information by confirming your identity through providing your email address, login credentials, bank account number or Social Security number (SSN).

Learn more personal information about you

With your phone number, scammers can go further in researching more of your personal information. They can enter your phone number on websites with information from public records to learn your full name, age, home address and more. The more information they find, the better idea they have about you to attempt to steal your identity.

Spoof your phone number to scam others

Scammers may use your phone number to make spoofed calls to your friends and family while impersonating you. When your loved ones receive a phone call from ‘you,’ the scammer will ask them for money due to an emergency or for personal information to commit more fraud.

Send you malware via text

You may receive a suspicious link through a text message. Scammers will send you these kinds of messages in smishing attacks to steal your personal information. Once you click on the link, malware will infect your device, read your messages and steal login credentials to your online accounts.

Protect your phone number from scammers

Scammers can use your phone number for a variety of reasons, including committing fraud, identity theft or hacking into your online accounts. Make sure you keep your phone number safe from scammers by placing a lock on your SIM card and securing your online accounts with strong passwords. You can generate and store strong, unique passwords by using Keeper Password Manager, which features a built-in password generator.

Start your free 30-day trial of Keeper Password Manager today to keep your personal information out of scammers’ hands.