“Evidently, sometimes people aren’t cleared to buy a firearm because of identity mixups. If you appeal, you may have to submit fingerprints, which will be checked through the criminal system.You can request the reasons for your denial, or challenge it, by writing to: Federal Bureau of Investigation NICS Operations Center Appeal Services Unit, Module A P.O. Box 4278 Clarksburg, WV 26302-9902 Include the NICS Transaction Number (NTN), available from the holder of the Federal Firearms License where you tried to buy the firearm. “