With additional reporting by Palash Volviokar
Our phones are the key to our digital identity. So it's no wonder they have become increasingly attractive targets for cybercriminals, who have a fair number of ways to take control of your phone number. People tend to refer to account takeovers as phone cloning, but they are actually talking about one of three things: phone cloning, SIM card cloning, or SIM card swapping.
True phone cloning involves copying the device information – the IMEI or ESN (electronic serial number), along with the MIN (mobile identification number) – to another device. In the past, this information was used to identify a device on cellular networks. However, advances in cellular networks and technology have made true phone cloning extremely unlikely in most countries, including the US.
SIM card cloning is also extremely rare. Modern SIM cards don’t just store your identifying information like a memory stick – they contain a secure chip with a secret authentication key that cannot be read or copied, even if someone removes the card and places it in a SIM reader. And as phones increasingly rely on encrypted, carrier-provisioned eSIMs instead of removable cards, physical cloning becomes even less realistic.
The biggest threat, and what you usually hear about, is SIM swapping. This is where hackers either go into a carrier store or call a carrier's customer support and impersonate account holders to get a new SIM. This method often relies on social engineering tactics to find out personal information that carriers use to authenticate customer accounts. And with the rise of eSIMs, attackers don't even need a physical SIM anymore – if they can breach your carrier account (through stolen or brute-forced credentials), they can remotely generate an eSIM QR code, scan it on their own device, and take over your number from anywhere.
Once someone has control of your phone number, they can send messages and make calls using it. The biggest danger is that text messages and calls intended for the rightful owner of the phone number are intercepted – including two-factor authentication codes that allow access to critical accounts like email, social media, crypto wallets, and even banking.
If you think a SIM swap is happening right now
- Call your carrier from another phone and ask them to freeze or restore your line immediately.
- Change your passwords and remove SMS-based two-factor authentication from critical accounts as soon as possible.
- Check your financial and social accounts for password reset emails or unfamiliar logins.
Read more: How to Back up Everything on Your Android Phone
5 signs that you may be a victim of SIM swapping, cloning, or eSIM hijacking
SIM-swap attacks tend to show up in very specific, very noticeable ways, usually all at once. The key is that your phone number stops working on your device because it’s been moved to someone else’s SIM. Here are the most common signs, in the order people usually notice them.
1. You stop receiving calls and texts
The first and biggest red flag is sudden loss of cellular service. Your phone shows “No Service,” you can’t make calls, and you can’t send or receive texts, even though you’re in an area where you normally have signal, and your account is paid up. Wi-Fi still works, but anything tied to your carrier does not.
2. You receive unexpected notifications from your carrier
FCC rules that took effect in 2024 require carriers to authenticate the person who requests any SIM change or number port-out. However, carriers often use security questions or details like your billing address, which isn’t hard to find or phish. If your number has been activated on a new device, your carrier will send a text or email confirming your details have been updated to the main account holder. So if your spouse is the main account holder, you may not receive any notice.
3. Unexpected password reset notifications from online accounts
The second wave of signs hits your online accounts. You’ll see unexpected password reset emails or security alerts, especially for email, banking, and crypto accounts. Attackers use your stolen number to intercept one-time passcodes sent via SMS, so they immediately try to reset your passwords.
4. You lose access to online accounts
Very quickly after that, you may lose access to your accounts entirely. You enter the correct password, but the 2FA code is sent to a number you no longer control. In some cases, you’ll get alerts that your email password, recovery email, or security settings have been changed.
5. You see unauthorized transactions in your financial accounts
Financial accounts are often targeted next. Watch for unauthorized transactions or transfer alerts, especially from banks, payment apps, or crypto exchanges. SIM-swap attacks are frequently used to bypass SMS-based security and move money.
There are also a few secondary warning signs that don’t always show up but are worth noting. Friends or colleagues might say they received strange messages from you, because attackers sometimes use the hijacked number to phish your contacts. And if you log into your Apple ID or Google account, you might see new or unfamiliar devices signed in, indicating broader account takeover beyond the phone number.
How to prevent SIM cloning and swapping
The single most effective step you can take to prevent a SIM swap is to set up your carrier's SIM protection and number lock features. All three major US carriers now offer free tools specifically designed to block unauthorized SIM changes and port-outs. If you haven't already, turn these on right now. It only takes a minute.
- AT&T's Wireless Account Lock is a toggle in the myAT&T app that locks SIM swaps, number transfers, and device upgrades on your account.
- Verizon offers both Number Lock (blocks port-outs to other carriers) and SIM Protection (blocks internal SIM changes). You can enable both through the My Verizon app under Settings.
- T-Mobile's SIM Protection, managed through the T-Life app, requires in-store verification with a photo ID to remove, which makes it pretty difficult for a hacker to bypass remotely.
The other simple step you can take is to set a PIN code that you must provide whenever you want to make a change to your account or to others on your plan. It isn’t a failsafe, since it could be phished, but it’s an extra layer of security that I recommend.
Finally, switch away from text-messaging-based two-factor authentication whenever possible. It’s the least secure 2FA method of protecting your accounts. At Techlicious, we recommend using passkeys. They're faster than typing a code, can't be intercepted through a SIM swap, and they are supported by Google, Apple, Microsoft, Amazon, and a growing number of financial institutions.
Read more: 2FA Explained: The Safest Ways to Protect Your Accounts
Updated on 2/26/2026 with eSIM hijacking threats, FCC-mandated carrier notification rules, carrier-specific SIM protection features, and passkey recommendations.
[Image credit: phone hacking concept via BigStockPhoto]
just get that spyware removed and put in a security measure to require your fingerprint for any app installation. Yes that includes those off the web as well
From Kammi Kothmann on April 08, 2020 :: 2:58 am
Im pretty sure my phone is cloned. i receive messages sometimes the day after they were sent. Voicemails i get later than they were made. i think i know who is doing it and im fixing to get a protective order put on them.
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From Josh Kirschner on April 08, 2020 :: 11:23 am
Delayed text messages and voicemails are not uncommon, and are usually due to issues on the carrier end. It’s much more likely that that is what’s happening to you versus phone cloning, which is very rare, only can be done with old devices, and wouldn’t necessarily result in delayed messages.
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From Marva Jane Theus on November 13, 2020 :: 4:41 am
My phone screen flashes when I go to certain pictures and certain text conversation…. My account is locked up and disable cause of the wrong passwords… It freezes and quite often pics and files are suddenly no longer in my phone
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From Angelica on November 23, 2020 :: 6:05 am
I’m sorry , I feel you . I am experiencing the same things . I have test and am milk her to gain access to my phone . Smh ! I know it’s my husband ... playing willing games . Uses my SIM card ! Cloned my phone ! Getting ready to validate this with an old time FEDeral friend and I’ll go from there . I’ll let you know the results ...
From Josie Gomez on August 05, 2021 :: 4:12 am
Aside from them changing my recovery number on Facebook making it impossible for me to verify its my account and it’s going to be deleted tomorrow if I can’t access it, I found 2 logins with the same phone. One has the picture of my phone, but the other was a different style phone but listed as an LG ThinQ like mine. Files have been deleted, modified or created. Then all my files, pictures and apps I found in a folder in my laptop. Then files that have sensitive information from clients with their banking, Passports, etc which I had put them all on a removable disk, where all on my laptop. These are 2015 files and my laptop is from 2019. It’s been going on every single day and I don’t know what to do.
From Butwhylil on October 22, 2022 :: 12:42 am
Give been experiencing the same problem for a few years now.my phones says t mobile not responding or my passwords are never working. I took it to metro in Memphis but they just said download an virus app. I fear in in danger and the people that murdered my family is the people around i fear my husband is being controlled by a family off cops that are trieng to set us up so we can’t testify these are the people that hurt us when I was little. Help me please.[personal information redacted]
Please we may be on catilina island or Cj tn
From Chad Vandine on February 13, 2021 :: 11:44 pm
My Aristo 5 was cloned onto an ihpone 11 somehow and was being used with roaming charges in Africa!
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From Dora on June 01, 2021 :: 11:55 am
Im confused. Why would you say only older phones cam be cloned? I had to send my phone in for repair. I was told by the 1st repair guy it was a cloned imei he believed. Is that not true?
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From Josh Kirschner on June 01, 2021 :: 6:47 pm
What we said was only older phones can be “remotely cloned”. It’s possible if someone has physical access to your phone that they may be able to clone the SIM on newer devices. I would be curious to know how the repair guy determined your phone had been closed.
From Kelly on August 05, 2021 :: 7:02 am
What about if you get random messages that your FaceTime is being used on another phone. And that your device has been signed in on another device. How do I stop this!?
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From Josh Kirschner on August 05, 2021 :: 5:56 pm
If you are getting a message saying your FaceTime is being used on another device, that sounds like your Apple ID may be compromised. Did you recently set up an Apple Watch or Mac with your Apple ID? If not, you should immediately change your Apple ID credentials. And always make sure you have two-factor authentication set up for your Apple ID to protect it.
From You know on September 01, 2022 :: 10:43 am
You are giving out no vibes of goodness….only excuses as to why U think it can’t be cloning….you are evil…you do it in large numbers…you are one of the cloning cunts yourself
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From J on October 12, 2024 :: 9:40 pm
They’re exactly right.
From Paula on October 02, 2022 :: 6:56 am
About two months ago my iphone started to do all kinds of things on its own and I kept getting security alertrs from my accts, etc etc… I reached out to anyone I could possibly think that could be a help or lead me to it… Well needless to say I got nowhere, mostly because everything required to go online and I could not do that with my devices, my husbands, I even went to family’s houses, libraries… This all sounded bizarre and I knew it was happening but nobody else did , I guess I can understand.. well here I am two months Into it and now my identity is exposed, I have bought 5 going on 6 cell phones in less than 2 months, and I have 3 smart tvs and they are all not working correctly and have installed software on them and I have no idea what to do or where to turn.. my phone keeps turning on sharing,, like location sharing, photo sharing, web activity share, and all kinds of weird permissions that I never even seen. Can someone please let me know what this is and how to stop it
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From PV on October 04, 2023 :: 4:35 pm
You’re living with a narcissist! Who will make every attempt to destroy your life! Get a restraining order and he’s tracking your device and he’s probably also in your Internet at home. That’s how he reconnect to your phone reset all of your wireless devices at home to brand new while your phone is off use cellular at home only not wireless and change providers on your wireless network, check your phones privacy settings if it’s an android you’re in trouble because of Google play services permissions if it’s an iPhone just take it to APPLE and have them give you a new Sim card and reset it change your ID and your password once you change providers everything changes your IP address. And if your phone is on his account, you’re not ever gonna get away from him.
From Tim Jackson on February 17, 2024 :: 5:43 am
I’m hoping someone can tell me what’s been done to my phone they got me into trouble so my freedom is riding on it. My ex gf got into my phone made herself the editor of my google account a Facebook account thru meta I slowly started getting emails from sites I hadn’t visited pictures would be in a different order phone getting hott poor performance then came the trouble w the law she sent videos and emails to herself but it looked like I done it my son told me he had seen her on my stuff but not my phone I discovered a bunch of files where it looks like they were running test to match my the computer side of it she had my voice recorded saying hello google she was watching me thru the camera listening to calls and just in general tracking everything where I went what I googled all of it im from a small town where the prosecutor don’t know shit so refused my evidence o have a mountain of it I need to know what was done and how they made it look like me oh and her bf owns a web business and 3 of her devices were connected to it including a computer please help me 🙏
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From Gregory Todd on April 03, 2024 :: 1:07 pm
I’m in the same boat I think I know who’s been cloning or hacking my phone and I’m getting tired of getting took,been ripped off by the same ex girlfriend for at least 300 bucks mostly from trying to send cash through cashapp,but I’m not sure the steps I should take to get them convicted or stopped and my phone fixed back the way it was it’s a real pain in the ass got any advice?
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