How Spam Callers Get Your Phone Number

Spam callers – or telemarketers, as they’re also known – are super annoying. But how do these spammers get access to your phone number?


In Chuck Palahniuk’s savagely hilarious novel, DAMNEDhe explains the origin of spam calls: they come from hell and are made by the damned souls that reside there, as penance for their lives of sin and evil.

There has never been a more apt thing written about telemarketers.

Most sane people often wonder why spam calling – or telemarketing, for that matter – is still legal. After all, it is a complete invasion of your privacy and it is always totally unwelcome.

Of course, there is a difference between a telemarketer and an actual spam caller; Telemarketing is legal and is done to promote an actual deal/offer, whereas spam callers are actively trying to defraud you, get access to your accounts, and generally ruin your life.

They’re both scum of the highest order. That goes without saying. But how do these spam callers get your number in the first place? Even people that are incredibly careful about giving out their number STILL get spam calls, so how does this happen?

How Do Spam Callers Get Your Number?

As with most things in life, there are a million and one ways your phone number can find its way into the hands of a spam caller – or a telemarketing company.

Some are obvious, but others will actually come as quite a shock to you. And while it is fairly easy to block spam callers on iPhoneit still pays to understand how spam callers get your phone number in the first place.

Here’s how spam callers get hold of your phone number…

1. They Bought It From Your Carrier

This doesn’t happen much anymore but back in 2018, a few major US carriers – AT&T, Verizon, Sprint and T-Mobile – were caught selling location data to third parties. And if that wasn’t enough, prior to 2016, they were also selling your phone number as well.

If you haven’t changed your phone number since before 2016, and you were with one of these major carriers then it is more than likely both your location AND your phone number were sold to third parties (meaning advert and marketing companies).

And this is why, despite all your careful measures, you still get spam callers. Thanks, AT&T, Verizon, Sprint, and T-Mobile!

two. Waiting Lists For Restaurants

Everybody likes a hot, new restaurant, right? If you live in a major city, they tend to pop up all the time. And they always have waiting lists. Fortunately, you can now use restaurant waiting list apps to book your table way in advance, saving you the headache of calling multiple times to secure a booking.

All good, right? Well, no, not really. Plenty of these restaurant waiting list apps have terms and conditions, you see, and these T&Cs are packed with all kinds of nefarious tidbits of information that most people just blindly ignore when they click ACCEPT after downloading the app.

Turns out plenty of these sorts of apps sell your data to third-party companies, so if you have used a restaurant waiting list app on your phone, chances are that app sold your data to spammers and telemarketers. This is why you ALWAYS read an app’s T&Cs.

3. 800, 888, and 900 Numbers

If you happen to call an 800, 888, or 900 number and the company or entity you’re calling isn’t exactly kosher, your phone number will be logged and saved by something called an Automatic Number Identification system (ANI).

The ANI will then match and pair your number to databases of online marketing companies. It finds the best fit for your number, based on its history, and then proceeds to sell the number to third parties, so they can start spam calling you with their terrible offers.

Four. Fake Charities (And Some Legit Charities)

Giving to charity is a fairly noble thing to do, even if you understand the reality of how many of them work – they’re basically just businesses that don’t pay tax.

Charities, large and small, often use third-party marketing companies to collect donations. As part of the deal, these marketing companies are allowed to keep aspects of the data they collect – your email, phone number, address.

From here, it is a simple process: the marketing company either sells your data to other marketing companies, or it uses the data it has collected to push its own marketing deals and offers onto you.

If you’re giving to charity, never give them your number and/or email.

5. Random Number Generators

You’ve heard of random number generators, right? Well, there is technology you can buy that will randomly generate phone numbers and call them with a script. This is less of a problem, to be honest, and can literally happen to anyone – it’s just luck of the draw, essentially.

If one of these machines is working 24/7, 365 days a year, it will potentially call millions of unsuspecting people. You could be one of those people. After all, there are only so many potential combinations of phone numbers.

How do you know if this has happened? It’s fairly simple: you pick up the phone to answer the call and you’re met with an automated message – it’s usually something about the IRS chasing you for back taxes or strange activity on your credit card and/or Amazon account.

If you’re gullible, you will then do what the automated message suggests and that is when the spammers will get you, harvesting your account details, your credit card number, or worse. If a call your receive is automated, just hang up and ignore it.

6. Data Breaches & The Dark Web

Data breaches happen all the time. It could be your local gym, Amazon, or even your bank. Hackers are ALWAYS looking for backdoors in websites and firewalls. When they find them, they get in, extract terabytes of information, and then proceed to sell it on the dark web.

Why do they do this? Money. Your data is worth A LOT of money to spammers and marketing companies. If you can extract the phone numbers of millions of Americans, you could make millions of dollars by selling them to spammers and criminals on the dark web.

This happens ALL THE TIME as well, so, as always, be very careful about who you share your phone number with – no company is ever completely safe and unhackable. For this reason, it sometimes pays to have two numbers, one for all your personal stuff and another you share with banks and other businesses.

7. Stupid Online Contests & Competitions

If you’re the type of person who enters contests, stop it – seriously, just stop doing it. The literal only reason competitions exist is to harvest your data, so that marketing companies can target you with adverts, deals, and offers. You never win, the marketing companies do.

This is one of the simplest and easiest ways for marketing companies and third parties to get your number. Once they have your number, they can A) spam you with deals, news, and offers or B) sell your number to other third-party marketing companies. Either way, you’re screwed.

Thankfully, it is actually really easy to block spam callers on iPhone.

Richard Goodwin

Richard Goodwin has been working as a tech journalist for over 10 years. He is the publisher and owner of KnowYourMobile.

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