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How Do We Detect a Number From a SIM Farm? There’s an API for That!

January 1, 2021

Telesign Team
An illustration of a farm with numerous SIM cards instead of crops.

As pretty much everyone today carries a smartphone at all times, they also carry a potential target on their back. SIM farm scams are taking aim at mobile phone users, and the problem isn’t going away anytime soon.

Here’s how the SIM farm scam works. Fraudsters buy thousands of SIM cards, activate them and then use them to verify new phone numbers during account registrations, opening you up to all kinds of fake user fraud. This attack circumvents basic user verification providers, but fortunately at Telesign we have a secret weapon: Subscriber Status.

Subscriber Status is an add-on functionality to our PhoneID API that allows us to know when a phone number was activated, so if a fraudster was activating thousands of SIM cards and attempting to register these numbers with accounts, we would know about it. Your platform would shut it down and fraudsters would have wasted a bunch of time and money on now worthless pieces of silicon.

Here’s how it works:

A diagram showing how the PhoneID system prevents SIM farm numbers.

If you’ve been following our ‘There’s an API for that!’ series from the beginning, you’ve learned how we verify phone numbers, detect virtual VOIP numbers, spot other shady phone numbers and even numbers that come from a SIM farm. That’s all great, but there is so much more our APIs can do. Next, we’ll talk about all the cool things you can do now that you have a verified phone number tied to each account.