Holders of an NRIC are responsible for the card's custody but are not required to carry the card on their person. Areas that will require NRICs to be verified include passports (immigration officers), polling stations (police officers) and those who undergo National Service in Singapore's Armed Forces, police force and civil defence force.^[3] Notwithstanding this, if no identification can be produced the police may detain suspicious individuals until such identification can be produced either in person or by proxy. It is also a requirement to re-register NRICs when 30 years old after completing the National Service. Since 1 January 2017, NRIC re-registration is required for those turning 55 years old.

Production of an NRIC is also required for any person seeking accommodation at any hotel, boarding house, hostel or similar dwelling place and for any person offering to pawn an article at a pawnbroker. In the case of hotels, boarding houses, etc., if a person is not in possession of, or fails to produce, an NRIC, the owner, manager or other person in charge of such business must notify the nearest police station of the fact immediately. Change of NRIC addresses is only mandatory when you fully move to the new address, but change of NRIC addresses is not mandatory when a family is split. This is to ensure that contact details can be traced in the event of emergency.

The NRIC is also sometimes a required document for certain government procedures or in commercial transactions such as the opening of a bank account. In addition, many businesses and other organisations in Singapore habitually request sight of an NRIC to verify identity or to allow a person entry to premises by surrendering or exchanging it for an entry pass. There is no legal requirement to produce the NRIC in these situations and often either providing any other form of identification (such as credit card, work or office pass, card with a photo on it) or simply providing an NRIC number (without producing the card itself) will suffice. From September 2019, organisations can no longer request and store NRIC numbers for such purposes, unless mandated by various laws.^[4][5]

The National Registration Act of 1965 (last amendment in 2001) legislates the issuance and usage of NRICs. Section 7 indicates that all registered persons of the national registry are to be issued with the identity card.^[6] The government agency responsible for the national registry is the Immigration and Checkpoints Authority (ICA), a department under the Ministry of Home Affairs.