Below is how to link your NIN to your various Sim cards: MTN, Airtel, Glo & 9mobile number using your phone:

FOR MTN:

Y’ello you can now link your National Identification Number (NIN) to your mobile number on the MTN network.
Simply dial *785# or visit https://t.co/YEwJL7ganf to get started pic.twitter.com/oYqh6s3dXZ
— MTN Nigeria (@MTNNG) December 17, 2020

Dial *785#
Enter your 11-digits NIN, and “Send”.
Note: You can as well visit https://mtnonline.com/nim and fill the online form to get it linked. Or call their customer care on 180.

2. FOR GLO:

You can now link your National Identification Number (NIN) to your mobile number as a Glo subscriber.

Simply send “UPDATENIN NIN FirstName and LastName” to 109.#ProtectYourNumber #SafetyForAll pic.twitter.com/O2FJNsxZ9G
— Gloworld (@GloWorld) December 18, 2020

To linked it to your Glo sim, you have to use a text message format;

Text “REG” to 746, and follow the subsequent instructions to get it linked

3. FOR 9MOBILE:

Stay connected.
Verify & link your National Identity Number (NIN) to your mobile number
dial *200*8# or visit https://t.co/1Jq0pcQ5au

To know your NIN status dial *346##HereForYou #9mobileNG #StaySafeStayConnected pic.twitter.com/EJgrxXXBU1
— 9MobileNg (@9mobileng) December 19, 2020

All you have to do is to;

Dial 200 (Customer service).
Follow the instructions, and speak with their representative to get it linked.
Verify & link your National Identity Number (NIN) to your mobile number dial 2008# or visit https://9mobile.com.ng/nin

4. FOR AIRTEL :

Here’s another way to link your National Identification Number (NIN) to your mobile number. Simply visit https://t.co/kBtTPcb8FT and follow the steps. pic.twitter.com/IZCwSHbBLq
— Airtel Nigeria (@AirtelNigeria) December 17, 2020

You can easily link your NIN to your Airtel SIM using your mobile phone. Follow the steps below to link your NIN to your Airtel phone number:

Dial *121# on your mobile phone and allow it to process,
Enter ‘1’ to select “NIN Capture”, and click on “Send” button.
When it opens, enter ‘1’ again to send
Enter your 11-digit NIN.
Here’s another way to link your National Identification Number (NIN) to your mobile number. Simply visit http://airtel.com.ng/nin and follow the steps.