You’d be forgiven if you’ve never heard of a phone “port-out” scam, because up until recently it wasn’t really a widely talked about issue. But it’s gotten serious enough that T-Mobile is sending warnings to many of its customers. Here’s a closer look at what this is and how to protect yourself from it.

What Is a Port-Out Scam?

If you want to switch cellphone carriers, you can typically bring your existing phone number with you—because who wants to get a new phone number if they don’t have to? No one, that’s who.

Now, imagine someone walking into a carrier store (or calling them) and pretending to be you. Without the proper security measures in place, this person could pretty easily steal your phone number and take it to a new carrier, effectively shutting off your phone service and taking control of your number. That’s pretty scary.

And that’s not the only type of porting scam in the wild today—there’s also something called a SIM swap scam (also called “SIM hijacking”) that works similarly, but instead of porting your number to a new carrier, the attacker simply pretends to be you and requests a new SIM card for your account. They get the SIM, they get access to your number.

And since only one SIM card can be attached to a number at any given point, it effectively disables your current SIM card. So while the tactic is slightly different, the end result is the same: your phone is disabled and someone else has your number as their own.

Why Is this a Big Deal?

While having your number hijacked and cell service terminated sounds like a headache, the implications are much deeper. Think about it: the hijacker just took control of your phone number, so they’re going to get access to all your calls and texts. Everything meant for your eyes or ears is now in the hands of a complete stranger. It makes my skin crawl just thinking about it.

And your private messages are the least of your worries. What if you use your phone number to receive text messages with security codes when you log into your bank account? That person now has access to any code sent to your phone, and can access your email, bank account, credit cards, and other super sensitive info.

That’s exactly why T-Mobile has recently¬†starting warning its customers about this issue. While it’s possible this could happen with any carrier, a flaw in T-Mobile’s system made it easier for attackers to port any number from a post-paid account to a new carrier, and some users have had their numbers compromised and their bank accounts cleaned out.

The company is doing things to correct the issue now, but it can still be a problem if you don’t know how to deal with it in the first place.

So How Do I Protect Myself?

The good news is that it’s pretty easy to protect yourself from this scam—you just need to make a quick phone call to customer service today, or make a tweak to your account online.

Basically, you need to add a security PIN to your account. The process is going to be different for every carrier (so we can’t outline them all here), but this PIN will be required to make changes to your account, which includes porting your number to a new carrier or requesting a new SIM card. Thus, it secures your account against both port-out and SIM swap scams. Good stuff.

Most carriers should let you do this online under some sort of account security setting, but if you can’t find this info online, just give them a quick call and let them know you want to add PIN security to your account. Remember, this PIN is different from the password you use when you log into your account: it’s specifically used when you walk into a store or call customer service to make changes.

Like with passwords and whatnot, choose something that isn’t easy to guess—don’t use your birthday, for example. That info isn’t hard to figure out, so it kind of defeats the purpose of setting the PIN in the first place. Once it’s in place, though, you should be better secured against this type of scam happening to you.

Image credit: Andrey_Popov/Shutterstock.com