How to link your National Identity Number – The Nigerian Communications Commission (NCC) had earlier mandated the telecommunications operators in the country to block all SIM cards that are not registered with the National Identity Numbers (NIN) within 2 weeks.

This means that failure of the subscribers to register with NIN will lead to the blocking or disconnection of the line by the end of December 31, 2020, despite the huge public outcry against the sudden announcement of the policy and short time frame to implement it.

The Nigerian Identity Management Commission (NIMC) have also directed that subscribers can link their NIN to more than one sim card. They said telecom subscribers should take their NIN to the office of their service provider.

However, some Nigerians who posses NIN are still unsure how to go about linking their phone numbers to their NIN
Source: https://www.cuzideas.com/link-your-national-identity-number-with-your-phone-number-free