The NIN (National ID Number) is while important is not intended to be a secret. The NIN is a 12 digit numeric number that would be issued at birth, and provided for the citizen throughout their life. The NIN is the Health1 ID Number, the licenses IDs, the photo ID, and even the bank account. The NIN is provided to any one that might need the card number, but keep in mind, the NIN is 1/3 of the information a bad actor needs to gain access to your account. So while it isn’t the only number, it should be provided only as needed, and only to people you trust.