How to Block Spam Calls in Korea — The Complete Guide

Living in South Korea means dealing with a constant stream of spam calls — loan offers, insurance pitches, and mysterious international numbers. According to the Korea Internet & Security Agency (KISA), hundreds of millions of spam calls and messages are recorded every year. Here's everything you need to know to fight back.

Top Spam Blocking Apps

WhoWho (후후) — 30M+ Users

WhoWho is Korea's most popular spam call identification and blocking app.

• Real-time caller ID: Instantly identifies incoming callers
• Automatic spam blocking: Filters numbers reported by the community
• KT integration: Pre-installed on KT carrier devices
• Free tier available: Core features are free, premium features for a subscription

Whoscall (후스콜) — App Store Award Winner

A globally recognized spam blocking app with a strong presence in Korea.

• Offline database: Identifies callers even without an internet connection
• Global coverage: Recognizes international spam numbers
• AI-powered filtering: Smart detection beyond simple blacklists
• Web lookup: Search unknown numbers through their website

Carrier-Specific Spam Blocking

SKT — T전화 (T-Phone)

SKT subscribers get a built-in spam blocking feature through the T-Phone app.

1. Open the T-Phone app
2. Settings → Enable Spam Blocking
3. Set blocking intensity (Low / Medium / High)
4. Add keyword filters to block SMS containing specific words

KT — WhoWho Integration

KT partners with WhoWho to offer integrated spam protection.

1. Install WhoWho or use KT's built-in calling app
2. Turn on spam blocking
3. Spam database updates automatically

LGU+ — U+ Spam Blocker

LGU+ offers its own dedicated spam blocking service.

1. Download the U+ Spam Blocker app
2. Verify your identity and activate
3. Automatic blocking + manual blocklist management

Built-In Phone Settings

Samsung Galaxy — Keyword-Based SMS Blocking

Samsung Galaxy phones have a powerful built-in text message filtering feature.

1. Messages app → Settings → Block numbers and messages
2. Add blocked phrases: Register keywords like "loan," "investment," "prize winner"
3. Messages containing those keywords are automatically blocked

iPhone — Silence Unknown Callers

iPhones offer a simple but effective spam reduction feature.

1. Settings → Phone → Silence Unknown Callers
2. Calls from numbers not in your contacts are silenced automatically
3. Callers are sent to voicemail for later review

⚠️ Note: This may also silence legitimate calls from delivery drivers or doctors. Check your voicemail regularly.

Official Reporting & Registration

KISA Spam Reporting

The Korea Internet & Security Agency operates a streamlined spam reporting system.

• Quick report: Forward spam texts to 118
• Online: Submit reports through KISA's Anti-Spam Center website
• Result: Reported numbers are investigated; fines may be issued

Do Not Call Registry (두낫콜)

To block telemarketing calls at the source, register with Korea's Do Not Call service.

• Website: donotcall.or.kr
• How to register: Verify your identity and register your phone number
• Effect: Telemarketers are legally prohibited from calling registered numbers
• Renewal: Re-registration required every 3 years

Spam Prevention Best Practices

Practice	Why It Matters
Don't answer unknown numbers	Answering confirms your number is active, inviting more spam
Minimize phone number exposure	Avoid entering your number on every website sign-up form
Be cautious with "free prize" events	These are often phone number harvesting schemes
Keep spam databases updated	Ensure your blocking app has the latest data
Check carrier add-on services	Many carriers offer free spam blocking add-ons

Keep Important Contacts Safe

When you aggressively block spam, you risk losing track of genuinely important numbers — hospital appointment lines, government offices, emergency contacts.

With LOCK.PUB, you can store a curated list of important contact numbers as an encrypted memo that only people with the password can access. Share the link via iMessage with family members so everyone has quick access to emergency numbers — even when their own phone isn't working.

Final Thoughts

Spam calls aren't just annoying — they can be a gateway to voice phishing (vishing) and financial fraud. By installing WhoWho or Whoscall, activating your carrier's spam blocking service, and registering with the Do Not Call registry, you can eliminate over 90% of spam.

While you're securing your phone against spam, consider organizing your essential contacts on LOCK.PUB so they never get lost in the noise. Start today — it takes less than five minutes.