SIM Swap Scams in South Korea
Criminals hijacking Korean mobile numbers to intercept OTP codes and drain online banking and crypto exchange accounts.
Part of: SIM Swap Scams
Last reviewed: 1 June 2026
SIM swap fraud in South Korea targets users of mobile banking services and cryptocurrency exchanges that rely on SMS one-time passwords. By taking over a victim's mobile number, fraudsters can intercept authentication codes from major Korean banks and crypto exchanges and drain accounts before victims realize what has happened.
South Korea's three major carriers — SK Telecom, KT, and LG U+ — have implemented security measures, but social engineering attacks on customer service remain a vector for unauthorized SIM transfers.
How this scam works on South Korea
Fraudsters gather personal information about the target — full name, resident registration number, and carrier account details — through phishing, data breaches, or social engineering calls. They then contact the carrier's customer service impersonating the account holder, requesting an emergency SIM replacement.
Once the new SIM is activated, the victim's phone loses signal. The fraudster uses intercepted OTP codes to access and drain Korean bank accounts (through internet banking) and crypto exchange accounts. With access to the victim's phone number, they may also take over KakaoTalk to scam the victim's contacts for emergency money transfers.
The speed of BI-FAST-equivalent Korean bank transfers (계좌이체) means that funds can be moved within seconds of gaining account access.
Common red flags
- Sudden loss of mobile signal without any network issue in your area
- SMS confirmation for a SIM change you did not request
- Bank or crypto exchange OTPs arriving for transactions you did not initiate
- KakaoTalk showing active session on unfamiliar device
How to protect yourself
- Set a carrier security PIN with SK Telecom, KT, or LG U+ to prevent unauthorized SIM changes
- Switch from SMS OTP to app-based authentication (OTP app) for banking and exchange accounts wherever possible
- Contact your carrier immediately if you lose signal unexpectedly
- Enable biometric authentication on all Korean banking and exchange apps
- Register for transaction alerts on all financial accounts
How to report it
- Contact your carrier's fraud line immediately
- Report to your bank's fraud hotline and request an emergency account freeze
- File with National Police Agency at police.go.kr or KISA at kisa.or.kr
Frequently asked questions
Can Korean carriers block SIM swap requests without the security PIN?
Yes — all major Korean carriers allow you to add a security PIN or verbal password that must be provided before any account changes. This is one of the most effective individual protections against SIM swap fraud.