Knowledge Center
Blog
What Are Spam Calls? The Complete Guide to Understanding and Stopping Unwanted Calls
Americans receive approximately 4 billion spam calls every month. That's not a typo—billion, with a B. In 2024 alone, the FTC fielded over 1.1 million complaints about unwanted calls, making illegal robocalls and phone spam the number one consumer complaint at the Federal Communications Commission.
If you've ever wondered what spam calls are, why you keep getting them, and whether anything can actually stop them, this guide covers everything you need to know.
What Is a Spam Call?
A spam call is any unwanted phone call, typically from telemarketers, scammers, or automated systems (robocalls) that you didn't request and don't want. Spam calls range from mildly annoying—legitimate businesses trying to sell you something—to outright dangerous scams designed to steal your money or personal information.
The term "spam" comes from email spam, where bulk unsolicited messages flood inboxes. Phone spam operates on the same principle: blast calls to as many numbers as possible, hoping some percentage will answer and engage.
What Does "Spam Call" Mean for Your Phone?
When your phone displays "Spam Risk," "Scam Likely," or similar warnings, it means your carrier's systems have flagged the incoming number based on calling patterns, reported complaints, or known scam databases. These labels help you decide whether to answer—but they're not foolproof. Legitimate calls sometimes get mislabeled, and sophisticated scammers constantly rotate numbers to avoid detection.
Types of Spam Calls
Not all spam calls are created equal. Understanding the different types helps you recognize threats:
Robocalls
Automated pre-recorded messages delivered by auto-dialer software. Some robocalls are legal—appointment reminders from your doctor, political campaign messages, or charity solicitations. But the vast majority of robocalls trying to sell you something are illegal under FTC rules.
Telemarketing Calls
Live salespeople calling to sell products or services. These can be legal if you have an existing relationship with the company or if you've given consent. However, calling numbers on the National Do Not Call Registry is illegal for most commercial purposes.
Scam Calls
Calls specifically designed to defraud you. Common scams include:
IRS impersonation: Threatening arrest for unpaid taxes
Tech support scams: Claiming your computer has a virus
Prize scams: Telling you that you've won a lottery you never entered
Grandparent scams: Impersonating a family member in trouble
Bank fraud alerts: Pretending to be your financial institution
Spoofed Calls
Calls where the displayed caller ID has been manipulated to show a different number—often a local number or a number belonging to a legitimate organization. Spoofing makes it nearly impossible to know who's really calling.
Why Do You Keep Getting Spam Calls?
Your phone number is more exposed than you think. Here's how spammers get it:
Data Breaches
When companies get hacked, customer databases—including phone numbers—end up for sale on dark web marketplaces. A single breach can expose millions of numbers overnight.
Data Brokers
Companies that legally collect and sell consumer information. Your number might be scraped from public records, social media profiles, or aggregated from various online forms you've filled out over the years.
Random Dialing
Some spam operations use auto-dialers that simply call every possible number combination in a given area code. They don't need your specific number—they just try them all.
Answering Spam Calls
Here's the cruel irony: answering a spam call often leads to more spam calls. When you pick up, your number gets flagged as "active" and becomes more valuable to sell to other spammers.
Online Forms and Contests
Every time you enter your phone number online—whether for a contest, a quote, or a "free" offer—that number potentially enters a marketing database that could be sold or breached.
How to Stop Spam Calls
Current spam-blocking solutions fall into three categories, each with significant limitations:
1. The National Do Not Call Registry
Registering at donotcall.gov tells legitimate telemarketers not to call you. The problem? Scammers don't care about the registry. They're already breaking the law—adding "violated Do Not Call list" to their crimes means nothing to them.
2. Carrier-Level Blocking
All major carriers now offer spam-blocking services:
Verizon: Call Filter
T-Mobile: Scam Shield
AT&T: ActiveArmor
These services analyze calling patterns and block known spam numbers. They help, but they're fighting a losing battle. Spammers constantly rotate through new numbers, and carriers can't block every spoofed call without also blocking legitimate callers.
3. Phone Settings and Apps
Both iPhone and Android offer built-in spam filtering:
iPhone: Settings → Phone → Silence Unknown Callers
Android: Phone app → Settings → Caller ID & spam
Third-party apps like Nomorobo, Hiya, and RoboKiller provide additional protection. But silencing all unknown callers means potentially missing important calls from numbers you don't recognize.
Why Traditional Spam Call Solutions Are Failing
Despite billions invested in spam-blocking technology, the problem persists. Here's why:
The Number Itself Is the Problem
Phone numbers were designed for an era when making calls was expensive and caller ID was trustworthy. Neither is true anymore. VoIP technology lets anyone make unlimited calls from anywhere in the world for pennies. Caller ID spoofing is trivially easy.
The fundamental issue: phone numbers have no authentication. When someone calls you, there's no cryptographic proof of who they are. Your phone displays whatever the caller wants it to display.
Spoofing Defeats Blocking
Spam blockers work by building databases of known bad numbers. But when spammers can instantly generate new spoofed numbers—often mimicking local area codes or legitimate businesses—those databases are always playing catch-up.
The Economics Favor Spammers
Even if 99.9% of spam calls get blocked, the 0.1% that get through can be profitable. With auto-dialers making millions of calls daily, even tiny success rates generate returns. The cost of making calls approaches zero, while the potential reward from a successful scam is substantial.
The Future: Why Secure, Authenticated Communication Matters
The spam call epidemic points to a deeper problem: our communication infrastructure lacks trust.
When your bank needs to contact you about a suspicious transaction, how do you know it's really your bank and not a scammer? You don't. And neither does your bank know if the person answering is really you.
This trust vacuum is why SIM-based authentication matters—not just for stopping fraud, but for enabling legitimate communication.
What Trusted Communication Looks Like
Imagine a world where:
Every message is cryptographically verified: You know exactly who's contacting you because the sender's identity is bound to tamper-resistant hardware
No spoofing is possible: Communication happens through secure channels that can't be impersonated
Two-way authentication: Both parties verify each other's identity before sensitive information is exchanged
This isn't hypothetical. The SIM card in your phone is already a secure element capable of cryptographic authentication. The infrastructure exists—it just hasn't been deployed for consumer communication.
Beyond Blocking: Building Trust
The long-term solution to spam calls isn't better blocking—it's better authentication. When legitimate businesses can prove their identity through hardware-based verification, and consumers can verify incoming communications are genuine, the spam call model breaks down.
Spammers succeed because they can impersonate anyone. Remove that ability, and the economics flip. Authenticated communication channels become valuable precisely because they're trusted.
Protecting Yourself Today
While we wait for authenticated communication to become mainstream, here's what you can do now:
Immediate Actions
Register with the Do Not Call Registry: Won't stop scammers, but reduces legitimate telemarketing
Enable carrier spam protection: Every major carrier offers free basic protection
Silence unknown callers: Accept that you'll need to check voicemail more often
Never engage with suspected spam: Don't press any buttons, don't say "yes," just hang up
Long-Term Habits
Minimize number exposure: Use a secondary number for online forms
Check your caller ID settings: Make sure spam filtering is enabled
Report spam calls: Forward suspicious texts to 7726 (SPAM), report calls to the FTC
Be skeptical of unexpected calls: Legitimate organizations don't demand immediate payment or threaten arrest
What Businesses Should Know
If you're a business trying to reach customers legitimately, the spam epidemic is your problem too. Consumers increasingly ignore unknown calls—including yours. Traditional phone outreach is becoming less effective precisely because bad actors have poisoned the well.
The solution isn't calling more aggressively. It's adopting communication channels that customers can trust. SIM-based secure messaging provides the authenticated, verified communication that phone calls simply can't offer.
The Bottom Line
Spam calls are a symptom of a broken trust model. Phone numbers were never designed to prove identity, and caller ID was never designed to be secure. Until communication channels include authentication at the hardware level, we're stuck playing whack-a-mole with spammers who have nothing to lose.
The technology to fix this exists. SIM cards are already secure elements capable of cryptographic verification. The question is how quickly businesses and carriers will adopt authenticated communication—and whether consumers will demand it.
Until then, keep your spam filters on and your skepticism high. If someone calls demanding immediate action, threatens consequences, or asks for sensitive information, hang up. Call the organization back using a number you know is legitimate.
The spam call era will eventually end. But it won't end with better blocking—it will end with better authentication.
Tired of spam calls ruining customer communication? Learn how SIM-based secure messaging creates trusted channels between businesses and customers →
