NICS Transaction Number
28 CFR § 25.2 [28 CFR PART 25—DEPARTMENT OF JUSTICE INFORMATION SYSTEMS]
NTN (NICS Transaction Number)
means the unique number that will be assigned to each valid background check inquiry received by the NICS. Its primary purpose will be to provide a means of associating inquiries to the NICS with the responses provided by the NICS to the FFLs.