NICS is used by Federal Firearms Licensees (FFLs) to instantly determine whether a prospective buyer is eligible to buy firearms. Before ringing up the sale, cashiers call in a check to the FBI or to other designated agencies to ensure that each customer does not have a criminal record or isn’t otherwise ineligible to make a purchase. According to the FBI, over 230 million such checks have been made, leading to more than 1.3 million denials.