SIM swapping
SIM swapping is a takeover attack in which a scammer talks a mobile carrier into moving your phone number onto a SIM card they control, bribes an insider to do it, or pulls it off with stolen account access. Once your number is theirs, your calls and texts land on their device, including the one-time codes used to reset passwords and approve transactions, opening the door to your accounts. The usual first sign is your own phone abruptly losing service.
How we check this: Written and reviewed by the Hunch team; recognition signs reflect how the FTC/FBI describe this scam. · Last reviewed: 2026-08
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Example
Your phone abruptly shows 'no service' for no clear reason. Meanwhile the attacker, now receiving your texts, requests password resets and captures the verification codes for your email, bank, and crypto accounts, locking you out and draining them.
How to recognize it
- Your phone unexpectedly loses signal or shows 'no SIM' or 'no service'
- You stop receiving expected calls and texts on your own device
- Password-reset or login alerts you didn't request start arriving
- You're suddenly locked out of email or financial accounts
How Hunch flags it
Hunch keys on the phishing and impersonation signals that often precede a swap, credential and verification-code asks, lookalike carrier or account pages, and urgency, that scammers use to gather the details needed to hijack a number.
FAQ
What is SIM swapping?
An attack that transfers your phone number to a SIM the scammer controls, so they receive your texts and calls, including verification codes, and can hijack your accounts.
How do I know if my SIM was swapped?
The clearest sign is your own phone suddenly losing service while you also start getting unexpected login or password-reset alerts.
How can I reduce the risk?
Add a PIN or port-freeze with your carrier and prefer app-based or hardware authentication over SMS codes for important accounts.