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Three layers of defense: SIM PIN prevents physical theft, CNAP shows you who's really calling, and an alternate number prevents SIM swap fraud. Enable all three today — it takes under 10 minutes total.

1. SIM PIN — Basic But Powerful

A SIM PIN is a 4–8 digit code that locks your SIM card. Every time your phone restarts, or someone inserts your SIM into a different phone, the PIN must be entered. Without it, a thief can put your SIM in any phone and receive all your OTPs immediately.

01
Open Settings
Settings → Security → SIM card lock (exact path varies slightly by Android version)
02
Enable SIM Lock
Toggle "Lock SIM card" ON. You'll be asked for the default PIN — most Indian carriers use 1234 as default. Enter it.
03
Change the Default PIN Immediately
Tap "Change SIM PIN" and set a new 6–8 digit PIN. Do NOT use 1234, your birthday, or your phone number. Write it down somewhere safe — 3 wrong attempts locks the SIM permanently (requires PUK code from your carrier).
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Done! Your SIM is now locked. Even if someone steals your phone and removes the SIM, they cannot use it without your PIN.

2. CNAP — Caller Name Display (Rolling Out Now)

CNAP (Caller Name Presentation) displays the KYC-registered name of the person calling you — directly on your incoming call screen, alongside their number. Unlike Truecaller which relies on crowdsourced data, CNAP uses the official government telecom database.

TRAI approved CNAP in October 2025. Jio, Airtel, Vi, and BSNL are piloting it in select circles. Full nationwide rollout is expected by March 31, 2026. You don't need to do anything — it will appear automatically on your phone once your carrier rolls it out in your circle.

What it shows
The name registered with your telecom KYC — so scammers pretending to be from "SBI" or "TRAI" are immediately exposed when their real name appears instead.
Privacy opt-out
Individual users can opt out of showing their name to others. Businesses cannot opt out — this is intentional to prevent corporate spam calls.

3. Alternate Mobile Number — Fraud Lifesaver

Registering a secondary number with your telecom operator is critical protection against SIM swap fraud. If a fraudster convinces your carrier to port or replace your SIM, your alternate number receives the alert OTP — giving you a chance to block it before damage is done.

🔵 Jio
MyJio App → Profile → Settings → Alternate Number → Add
🔴 Airtel
Airtel Thanks App → Account → Manage → Alternate Contact → Update
🟣 Vi
Vi App → Account Settings → Alternate Number → Add
🟠 BSNL
Call 1503 from your BSNL number, or visit your nearest BSNL Customer Service Centre

Use a trusted family member's number or a second SIM you own as your alternate. Do not use the same number you're registering the alternate for.

Frequently Asked Questions

What if I forget my SIM PIN?

After 3 wrong attempts, your SIM locks permanently and requires a PUK (Personal Unblocking Key) code. Call your carrier's customer care (Jio: 199, Airtel: 121, Vi: 199, BSNL: 1500) to get your PUK. This is why writing your PIN down safely is important.

Can I set SIM PIN on iPhone?

Yes. Settings → Mobile Service → SIM PIN → Enable. The path is slightly different but the feature works identically.

Does CNAP work with VoIP or internet calls?

No. CNAP only applies to regular cellular calls routed through your carrier's network. WhatsApp calls, Truecaller Voice, and other app-based calls are not covered.