The National Identification Number (NIN) is the unique number which identifies everyone as a Nigerian and is issued to you at the completion of enrolment into the National Identity Database (NIDB) by NIMC.
HERE ARE WAYS TO AVOID YOUR SIM FROM GETTING BLOCKED;
1. Enroll for your national identification card
2. Make sure you monitor your sim activities
3.Borrow money like 1-2 thousand from your sim as popular nigerian singer and songwriter erigga said on his latest tweet