Phone Number Spoofing Explained

Caller ID spoofing is the practice of changing the phone number that appears on a recipient's caller ID display. Here's how it works and why scammers use it.

How Spoofing Works

When you make a phone call, your carrier sends your phone number as the "calling party number" to the receiving carrier, which displays it on the recipient's caller ID. Spoofing services intercept this process and replace the real number with a different one.

Scammers typically use VoIP (Voice over IP) services that allow programmatic control over the caller ID field. Some services allow changing the caller ID to any number — including your own area code, a local business number, or even a government agency number.

Why Scammers Spoof Numbers

Trust: People are more likely to answer calls from local numbers. A call from your own area code feels familiar and safe, even though the caller could be anywhere in the world.

Impersonation: By displaying a bank's real phone number, a scammer can make you believe the call is actually from your bank. The same technique works for the IRS, Social Security Administration, or any other entity.

Avoiding blocks: Even if you block a spoofed number, the scammer simply uses a different one next time. They have an essentially unlimited supply of numbers to display.

Legal vs. Illegal Spoofing

Spoofing itself is not illegal in all cases. Businesses legitimately use it to display a main office number instead of individual extensions. Doctors calling from personal phones may display their office number for privacy. Law enforcement may use it during investigations.

However, the Truth in Caller ID Act of 2009 makes it illegal to spoof a number "with the intent to defraud, cause harm, or wrongfully obtain anything of value." Penalties can reach $10,000 per violation, plus criminal charges.

How to Identify Spoofed Calls

The callback test: If you miss a call and call back, and the person who answers has no idea what you're talking about, the original call was likely spoofed using their number.

Mismatched information: If the caller claims to be from the IRS but the caller ID shows a cell phone number, or claims to be from New York but the area code is from Texas, the call is likely spoofed.

Search the number: Use our lookup tool to check if a number has been reported as spoofed by other users. Community reports often identify numbers being used in active spoofing campaigns.