Complete Guide to Mobile Number Theft Prevention
Comprehensive guide to preventing mobile number theft and SIM swapping.
Mobile number theft prevention is an essential security service that proactively blocks others from fraudulently using your phone number for identity theft, unauthorized micropayments, or identity verification abuse.
Table of Contents
1. Service Overview
Mobile number theft prevention is a protection service that guards against identity theft, micropayment fraud, and unauthorized identity verification.
[Threats It Blocks]
• Unauthorized account registration using your identity
• Unauthorized micropayment charges
• Unauthorized identity verification attempts
• Smishing (SMS phishing) attacks
• Secondary damages from voice phishing
[Service Providers]
Ministry of Science and ICT
Korea Information and Communication Technology Association (KICTA)
Major carriers: SKT, KT, LG U+
[Cost]
Completely free
2. How to Sign Up and Set Up
[Online Registration (Recommended)]
1. Visit the MSAFER website
• msafer.or.kr
2. Identity Verification
• Mobile phone authentication
• Accredited certificate
3. Apply for Protection Services
• Identity theft prevention
• Micropayment blocking
• Identity verification service restriction
4. Immediate Activation
• Protection begins as soon as registration is complete
[Carrier App Registration]
SKT: T World > Add-on Services
KT: Olleh KT > Security Services
LG U+: U+ Customer Center > Number Protection
[In-Person Registration]
• Visit a carrier store
• Bring your ID
3. Key Features and How to Use Them
[1. Identity Theft Prevention]
• Blocks others from opening a new phone line in your name
• Requires additional verification during new registrations
• Prevents illegal burner phone activation
[2. Micropayment Blocking]
• Set monthly spending limits (0–500,000 KRW)
• Block specific categories (games, adult content, etc.)
• Require additional authentication at checkout
[3. Identity Verification Service Restriction]
• Blocks third-party identity verification attempts
• Sends alerts on verification attempts
• Selectively allow trusted services (banking, shopping, etc.)
[4. Real-Time Alerts]
• Instant notifications for suspicious activity
• Alerts via SMS and KakaoTalk
• View activity logs anytime
4. Detailed Settings and Management
[Setting Micropayment Limits]
1. Log in to MSAFER
2. My Page > Micropayment Management
3. Set monthly limit
• 0 KRW (fully blocked)
• 300,000 KRW (default)
• 500,000 KRW (maximum)
[Managing Allowlist]
• Allow only trusted sites
• Financial institutions automatically allowed
• Government agencies automatically allowed
[Temporary Suspension]
• Temporarily suspend for online purchases
• Disable for 1–24 hours
• Automatically reactivates afterward
[Family Account Management]
• Protect accounts for minor children
• Parents can configure settings on their behalf
• Available for users aged 14 and older
5. Responding to Fraud and Disabling the Service
[If You Become a Victim of Identity Theft]
1. Contact your carrier customer service immediately
• SKT: 114
• KT: 100
• LG U+: 101
2. File a police report (112)
• Report cybercrime
• Report to the Financial Supervisory Service (1332)
3. Dispute Unauthorized Charges
• Request billing adjustment from your carrier
• Submit supporting documentation
4. Check Your Credit Report
• NICE Credit Information
• Review your personal credit file
[Disabling the Service]
• Can be disabled at any time when needed
• Via MSAFER or your carrier app
• Protection stops immediately upon disabling
[Caution]
Disable with care — staying protected is always the safer choice.
Key Tips
- •This service is free for all citizens — make sure to sign up
- •Set your micropayment limit to 0 and temporarily suspend it only when needed
- •Regularly check your authentication history on MSAFER
- •Have your entire family sign up to protect against voice phishing scams
- •If your ID or phone is lost, immediately check your theft prevention service
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Have any questions?