What is Caller ID Spoofing?

Spoofed calls

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Spoof calls manipulate caller ID Name (CNAM) to mask the caller’s real number, misleading recipients. This technique is not just annoying, but it often leads to scams.

Many businesses use caller ID spoofing for different reasons. Legitimate companies may use it to display a familiar number to customers. What’s more concerning is its use by scammers and fraudsters. They misuse this technology to commit fraud, steal data, and illicitly obtain money from unsuspecting individuals.

What Is Call ID Spoofing?

Call ID spoofing is altering the phone number shown to the call recipient. Instead of displaying the real number, it shows a different one, hiding the caller’s identity. It makes the incoming call appear as if it’s coming from someone else, possibly someone the receiver knows or trusts. The main goal is to deceive the recipient about the call’s origin.

History of Phone Number Spoofing

Over the years, law enforcement officials and collection agencies have utilized caller ID spoofing to mask their actual numbers. These entities used it to increase the likelihood of their calls being answered. It laid the groundwork for what was to come. In 2004, a historic moment occurred with the launch of Star38.com, the first service specifically designed to offer caller ID spoofing for the general public. Soon after, similar services skyrocketed, dramatically increasing the ease of executing spoof calls.

Accessibility to spoof calling led to a spike in scams, particularly noted in online marketplaces like eBay and Craigslist. Fraudsters often pose as buyers from reputable locations to gain sellers’ trust and personal information and then use it for fake sale schemes.

One of the most significant impacts of caller ID spoofing was seen in the 2015 IRS scam when scammers spoofed the IRS’s phone number to call thousands of Americans. They claimed they owed back taxes and demanded immediate payment. The 2015 IRS scam highlighted the growing issue of caller ID spoofing and its potential for significant harm.

With technology advancements, Caller ID Authentication and spam detection apps have emerged to combat scam calls, yet caller ID spoofing remains a challenging issue.

How Do Scammers Spoof Phone Numbers?

Scammers spoof phone numbers using VoIP technology and third-party caller ID spoofing apps that manipulate the caller information when displayed on the receiver’s screen.

VoIP services are a great alternative to traditional phone services. Still, due to its easy setup and low costs, scammers use them to impersonate someone else by customizing their caller ID display name during account setup.

In addition to VoIP technology, scammers employ third-party apps. First, the individual intending to spoof a call employs either software or a web-based service designed for this purpose. These tools are crafted to interact with the telecommunications network. They allow users to specify any number they want to appear on the recipient's caller ID display.

After initiating the call, the spoofing technology intervenes by instructing the telephone network to substitute the caller's real number with the chosen, deceptive number. This manipulated number is what the recipient sees, leading them to believe the call is originating from a different source.

Is Number Spoofing Legal?

Under the Truth in Caller ID Act of 2009, number spoofing is illegal if the person uses a misleading caller ID with the intent to defraud, manipulate, or harm. The act provides exceptions for authorized activity of a law enforcement agency, a court order, or legitimate business needs.

Legally, your business can employ caller ID spoofing for good reasons, like ensuring that a returned call goes to a business's customer service line rather than a specific employee's phone or to protect an individual’s privacy in sensitive situations. Despite these legitimate applications, the rise in fraudulent activities has prompted regulatory bodies to enforce stricter guidelines and penalties for misuse. Intent plays a crucial role here. If the call spoofers intend to deceive, harm, or unlawfully gain from the recipient, it falls under illegal acts and is punishable by law.

Any person who knowingly violates the law can be fined up to $10,000 for each violation or 3 times that amount for each day of a continuing violation.

How Is Caller ID Spoofing Misused?

Caller ID misuse ranges from harmless pranks to serious fraud, using a trusty number for deceit.

1. Identity Theft

Fraudsters can spoof calls to steal sensitive personal data and information. For instance, they can pose as representatives from banks or trusted institutions to trick you into revealing sensitive information like social security numbers or bank details. It can lead to financial loss and compromised personal security.

2. Harassment

Spoof calls may include relentless calls that harass or intimidate the receiver. By hiding behind familiar or authoritative numbers, the spoofers make unwanted advances and threats or simply disturb your peace.

3. Spread of Misinformation

Spoof calls allow the spread of false information by impersonating credible sources. During events like elections or crises, calls that appear to come from legitimate organizations can mislead recipients about critical issues, influencing opinions and behaviors based on deceit.

4. Emergency Scams

Emergency scams exploit your concern for loved ones by faking emergencies. Call spoofer claims to be your family members or authorities reporting an accident or legal trouble, urgently requesting money for help. The spoofed ID lends credibility to these lies, influencing you to act without verification.

How To Identify a Spoof Call?

Watch for odd personal or financial information requests and rushed decisions to identify a spoof call. Remember, legitimate calls typically offer validated time to make any decisions.


  • Unexpected Requests for Personal Information: If a caller, claiming to be from a trusted organization, unexpectedly asks for personal details or financial information, it could be a scam call.
  • Pressure Tactics: Scammers often create a sense of urgency, pressuring you to act immediately. Legitimate organizations understand the need for due diligence.
  • Mismatched Information: If the caller’s story doesn't add up or you receive conflicting information, it’s a red flag. For instance, a bank calling from an unrecognized number asking for your account details.
  • Inconsistencies: Scammers might not have all the correct information. Asking detailed questions about the account or service they claim to represent can reveal fraud.
  • Use Call-Identification Apps: Different free spoof call detector apps are available; use them to screen potential spam calls.

What Happens When You Pick Up a Spoofed Call?

Answering a spoofed call can lead to scams or more unwanted calls, signaling to fraudsters that your number is active.

When you pick up a spoof call from a scammer, they may attempt to deceive you by pretending to be from a trusted organization to steal your personal information or money. They might ask for sensitive details, claim an urgent problem requires immediate action, or even threaten legal action to pressure you into complying. Even if you don't give out any information, just picking up the call can be enough for some scammers to attempt to charge high fees to your phone bill through premium rates or other means.

What to Do If You Pick Up a Spoof Call?

If you answer a spoof call, hang up immediately without engaging; then report the number to the Federal Communication Commission (FCC) to prevent future scams.

1. Do Not Share Personal Information

Never provide sensitive details like your social security number, bank account information, passwords, or other personal data unless you're absolutely sure of the caller's identity and legitimacy.

2. Document and Report

Note the caller’s number and any relevant information about the conversation, then report it to the FCC and your service provider.

3. Educate and Protect

Increase awareness of common fraudulent schemes and use call-blocking tools to minimize risks. Share your experience with others to spread awareness.

4. Seek Further Action if Necessary

If you’ve inadvertently shared personal information, monitor your accounts for unusual activity and consider measures like freezing your credit to prevent unauthorized use.

Protecting Yourself Against Spoof Calls

To prevent spoof calls, avoid answering calls from unknown numbers. Limiting sharing your phone number online and in public records can further decrease the chances of receiving unwanted calls. Additionally, you can equip your phone with apps designed to identify and block potential scam calls. Such apps can serve as an effective barrier against fraudsters. Calilio offers a VoIP phone system with Caller ID Authentication that verifies incoming calls, preventing potential spoof calls.

Frequently Asked Questions

What is a spoofing phone call?

Caller ID spoofing is the intentional act of falsifying the information displayed in the Caller ID to hide the caller’s true identity.

What happens if I answer a spoof call?

If you answer a spoof call, you will only necessarily be at risk once you answer personal and financial information or send them money.

Can I stop my phone number from being spoofed?

You cannot completely stop your number from being spoofed, but you can take preventive measures to decrease the chances. Avoid online competitions, do not answer calls from unknown numbers, and block spam numbers on your phone.

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