In today's digital world, protecting your personal information is essential. Your Aadhaar card contains sensitive data, including biometric details like your fingerprint and iris scan.  

To prevent unauthorised use of this data, you can lock your Aadhaar biometrics. This simple step helps keep your information safe from misuse.   

This guide covers important information to help you lock your Aadhaar card through the UIDAI website, mAadhaar app, and SMS service, plus troubleshooting common issues.   

Aadhaar lock is a security feature from UIDAI that temporarily disables biometric authentication. When locked, nobody can authenticate the card using your fingerprint or iris scan for any service, including banking transactions, SIM activation, or government services. 

The feature addresses a critical vulnerability. Unlike passwords that you can change, biometrics remain constant. If someone captures your fingerprint data, they could potentially misuse it indefinitely. Locking prevents such misuse entirely. 

What Biometrics Can Be Locked? 

The Aadhaar card security lock covers fingerprint data (all ten fingers) and iris scan data (both eyes). 

Demographic authentication (name, address, date of birth) remains unaffected. Services using OTP-based verification continue working normally. 

When locked, any attempt to authenticate using your biometrics shows an error code 330 (biometrics locked by user). 

Difference Between Aadhaar Number and Virtual ID 

Virtual ID (VID) adds another security layer: 

Aadhaar Number: permanent 12-digit identifier. 

Virtual ID: temporary 16-digit number mapping to Aadhaar. 

VID can be used instead of Aadhaar number for most authentications. It can be revoked and regenerated anytime, unlike the permanent Aadhaar number. 

Using VID for transactions while keeping biometrics locked provides maximum security. 

Protection Against Identity Theft and Fraud 

Biometric locking prevents unauthorised SIM cards issued in your name, fraudulent bank account openings, property registration fraud, fake insurance claims, and government benefit diversion. 

Cases of Aadhaar-based fraud have appeared in news reports. Criminals have used cloned fingerprints to withdraw money, activate SIMs, and commit property fraud. Locking eliminates this attack vector. 

Privacy and Security Benefits 

Beyond fraud prevention, Aadhaar lock offers control over when your biometrics can be used, protection against data breaches at authentication points, and peace of mind when sharing Aadhaar for KYC. 

You unlock temporarily when needed, complete authentication, then relock immediately. This minimises the window for potential misuse. 

Impact on Aadhaar-based Services 

When biometrics are locked: OTP-based authentication works normally, demographic authentication continues, but fingerprint/iris authentication fails with error 330. 

Services requiring biometric verification will not work until you unlock. Plan accordingly before visiting banks or government offices needing fingerprint authentication. 

Requirements Before Locking Aadhaar 

Before attempting how to lock Aadhaar card, ensure: mobile number registered with Aadhaar (for OTP), 12-digit Aadhaar number or 16-digit VID, active internet connection, and access to UIDAI website or mAadhaar app. 

Without registered mobile, you cannot lock or unlock biometrics online. Visit an Aadhaar enrolment centre to update mobile number first. 

Step-by-Step Guide Using UIDAI Website 

Follow these steps to lock via website: 

Step 1: Visit myaadhaar.uidai.gov.in. 

Step 2: Click on “Login” and enter your 12-digit Aadhaar number. 

Step 3: Complete CAPTCHA verification. 

Step 4: Request OTP on registered mobile number. 

Step 5: Enter OTP and login to your dashboard. 

Step 6: Navigate to “Security Settings” section. 

Step 7: Find “Lock Biometrics” option and click. 

Step 8: Confirm your choice when prompted. 

Step 9: Receive confirmation message on registered mobile. 

Your biometrics are now locked. Any authentication attempt using fingerprint or iris will fail. 

Using mAadhaar App to Lock Biometrics 

The mAadhaar app provides convenient mobile access: 

Step 1: Download mAadhaar from Google Play Store or Apple App Store. 

Step 2: Open app and set 4-digit security PIN. 

Step 3: Add your Aadhaar profile using OTP verification. 

Step 4: Once profile loads, go to “My Aadhaar” section. 

Step 5: Select “Biometric Lock” option. 

Step 6: Toggle to enable lock. 

Step 7: Authenticate using OTP. 

Step 8: Receive confirmation of successful locking. 

The app shows lock status in real-time. You can toggle lock and unlock from the same screen. 

Locking Aadhaar Biometrics via SMS 

For users without internet access, SMS locking works: 

To Lock: Send SMS: LOCK [last 6 digits of Aadhaar] to 1947. 

Example: LOCK 567890 to 1947. 

Send from Aadhaar-registered mobile number only. You receive confirmation SMS within minutes. 

Note: SMS service has limitations. For full control including unlock, website or app is recommended. 

When and Why to Unlock 

Unlock biometrics when visiting bank for biometric-authenticated transactions, getting new SIM card requiring fingerprint verification, applying for government services needing biometric KYC, or any authentication requiring fingerprint or iris. 

Unlock temporarily, complete your work, then relock immediately for continued protection. 

Unlocking Through UIDAI Website 

Step 1: Login to myaadhaar.uidai.gov.in using Aadhaar and OTP. 

Step 2: Navigate to “Security Settings.” 

Step 3: Find current lock status showing “Locked.” 

Step 4: Click “Unlock Biometrics” or “Enable Biometrics.” 

Step 5: Confirm through OTP authentication. 

Step 6: Choose unlock duration (temporary or permanent). 

Temporary unlock disables lock for 10 minutes, then auto-relocks. Permanent unlock keeps biometrics enabled until you manually lock again. 

mAadhaar App Unlock Process 

Step 1: Open mAadhaar app and login with PIN. 

Step 2: Go to “Biometric Lock” under “My Aadhaar.” 

Step 3: Toggle to disable lock. 

Step 4: Authenticate via OTP. 

Step 5: Choose temporary (10 min) or permanent unlock. 

The app displays countdown timer during temporary unlock period. 

Unlocking via SMS Service 

Send from registered mobile: 

To Unlock: Send SMS: UNLOCK [last 6 digits of Aadhaar] to 1947. 

Example: UNLOCK 567890 to 1947. 

SMS unlock is permanent. Remember to relock manually via SMS or other methods after completing authentication. 

Generating and Using Virtual ID 

VID generation process: 

Step 1: Login to myaadhaar.uidai.gov.in. 

Step 2: Go to “VID Generator” section. 

Step 3: Request new VID using OTP. 

Step 4: 16-digit VID sends to registered mobile. 

Use VID instead of Aadhaar number for bank account opening, mobile SIM registration, government scheme enrolment, and any eKYC process. 

The agency cannot retrieve your actual Aadhaar number from VID. This protects your permanent identifier. 

Role of VID in Locking/Unlocking Aadhaar 

VID can be used for unlocking biometrics temporarily, accessing UIDAI services without exposing Aadhaar, and authentication at service points. 

Some lock/unlock functions accept VID instead of Aadhaar number, adding convenience without compromising the 12-digit permanent identifier. 

Advantages of Using VID Over Aadhaar Number 

Benefits of VID usage: revocable (generate new VID anytime, old one becomes invalid), limited exposure (agencies see VID, not actual Aadhaar), traceability (different VIDs for different services if needed), and same functionality (works for all authentication purposes). 

Combine VID usage with biometric locking for maximum protection. 

Understanding Biometric Lock Error Code 330 

Error 330 appears when your biometrics are locked (intentional), service provider attempts fingerprint/iris authentication, and system rejects authentication automatically. 

This error is expected behaviour when locked. Simply unlock temporarily to proceed with authentication. 

What Happens When Biometrics Are Locked 

With active Aadhaar card security lock: OTP-based eKYC works normally, demographic authentication works normally, fingerprint authentication returns error 330, iris authentication returns error 330, and face authentication works (not covered by biometric lock). 

Plan authentication method before visiting service centres. 

Troubleshooting Lock/Unlock Failures 

OTP not received: Check if mobile number is registered with Aadhaar. Ensure network connectivity. Wait 30 seconds and retry. Try alternate method (SMS if online fails). 

Website errors: Clear browser cache and cookies. Try different browser. Use mAadhaar app as alternative. Attempt during non-peak hours. 

mAadhaar app issues: Update to latest version. Ensure mobile data connection (Wi-Fi has limitations). Reinstall app if persistent errors. Contact UIDAI helpline 1947. 

Registering Mobile Number and Email for OTP 

Ensure contact details are current. Mobile number is essential for OTP authentication. Email provides alternative communication channel. 

Update at Aadhaar enrolment centre if details changed. Online update available for address only. 

Using Time-based OTP (TOTP) 

TOTP generates OTP within mAadhaar app. Works offline once generated. Changes every 30 seconds. No dependency on SMS delivery. Faster than waiting for SMS. 

Enable TOTP in mAadhaar for quicker authentications. 

Safe Sharing Practices and Awareness 

Protect your Aadhaar by never sharing OTP with anyone calling as bank/government official, using masked Aadhaar (showing only last 4 digits) for general purposes, avoiding Aadhaar sharing on unsecured websites, checking authentication history regularly in mAadhaar, and reporting suspicious activity to UIDAI immediately. 

Aadhaar is sensitive identity information. Treat it with same caution as bank account details.