Understanding the NICS Background Check System

Every time you purchase a firearm from a licensed dealer — whether at a gun shop, gun show, or online transfer — you undergo a background check through the National Instant Criminal Background Check System (NICS). Here's exactly how it works, what can go wrong, and what to do if you're wrongly denied.

By Dwight Ringdahl — GunExpos.com

What Is NICS?

The National Instant Criminal Background Check System is a database maintained by the FBI that determines whether a prospective buyer is eligible to purchase a firearm under federal law. NICS was established by the Brady Handgun Violence Prevention Act of 1993 and has been operational since November 30, 1998.

NICS checks are performed when you buy a firearm from any Federal Firearms Licensee (FFL). In some states, the check is performed directly by the FBI. In others, the state acts as a "point of contact" (POC) and conducts its own check using NICS data plus state-specific databases.

How the Process Works

Step 1: You Complete ATF Form 4473

When you decide to purchase a firearm from an FFL, you fill out ATF Form 4473 — the Firearms Transaction Record. This form collects your personal information and asks a series of eligibility questions (are you a felon, are you under indictment, are you a fugitive, etc.).

You must answer every question truthfully. Lying on a 4473 is a federal felony punishable by up to 10 years in prison and a $250,000 fine.

Step 2: The Dealer Initiates the Background Check

The dealer submits your information to NICS via one of two methods:

  • Phone call — The dealer calls the FBI's NICS Operations Center and provides your information verbally to an examiner
  • E-Check — The dealer enters your information into the NICS E-Check web portal

In POC states, the dealer contacts the state agency instead of the FBI directly.

Step 3: NICS Searches Multiple Databases

The NICS system searches three primary databases:

  1. NICS Index — A database of individuals specifically prohibited from possessing firearms (maintained by the FBI with records from federal and state agencies)
  2. National Crime Information Center (NCIC) — FBI's criminal justice database containing wanted persons, protection orders, and other records
  3. Interstate Identification Index (III) — A pointer system that identifies which states hold criminal history records for an individual

The search checks for any record that would make you a "prohibited person" under federal law.

Step 4: NICS Returns a Result

The background check returns one of three results:

The Three NICS Results

PROCEED

What it means: You are approved to purchase the firearm. No prohibiting records were found.

Timeline: Most PROCEED results come back within minutes — often under 30 seconds for the electronic check. This is why it's called the "instant" check.

What happens next: The dealer completes the sale, records the NICS transaction number (NTN) on the 4473, and releases the firearm to you (subject to any state waiting period).

DELAYED

What it means: The system found a record that requires additional review by a NICS examiner. This does NOT mean you're denied — it means the automated system couldn't make a definitive determination and a human needs to review your record.

Common reasons for delays:

  • Common name that matches another person's record
  • Arrest record without a documented final disposition (the system can't confirm the outcome of the case)
  • Active or expired protection order that needs verification
  • Mental health records that require clarification
  • Previous military service with a discharge that needs classification verification
  • Prior drug-related contacts that need disposition verification

Timeline: The FBI has up to 3 business days to make a final determination. During this period:

  • If the FBI issues a PROCEED within 3 business days → the dealer completes the sale
  • If the FBI issues a DENY within 3 business days → the dealer cannot complete the sale
  • If 3 business days pass with no response → the dealer may (but is not required to) complete the sale at their discretion. This is called the "default proceed" or "Brady date" provision.

Important: Many dealers will NOT proceed after the 3-day window — they choose to wait for a definitive answer. This is their right.

If no final answer comes within 88 days, the FBI purges the transaction. If the dealer has not yet transferred the firearm, the buyer would need to start a new 4473 and a new background check.

DENIED

What it means: The NICS check found a record that makes you a prohibited person under federal law. The dealer cannot complete the sale.

Common reasons for denials:

  • Felony conviction
  • Felony indictment
  • Domestic violence misdemeanor conviction
  • Active protection/restraining order
  • Fugitive from justice
  • Unlawful user of controlled substances
  • Adjudicated as mentally defective or committed to a mental institution
  • Dishonorable military discharge
  • Renounced U.S. citizenship
  • Illegal alien or nonimmigrant visa holder (with exceptions)

What to Do If You're Wrongly Denied

False denials happen more often than you might expect. The FBI's own data shows that approximately 2–3% of initial denials are later overturned on appeal. Common causes of false denials include:

  • Name match — Someone with a similar name, date of birth, or Social Security number has a prohibiting record
  • Incomplete records — An arrest record exists but the favorable disposition (dismissal, acquittal, expungement) wasn't uploaded to NICS
  • Mistaken identity — Someone else's record is incorrectly linked to your identity
  • State reporting errors — State agencies sometimes submit incorrect or incomplete records

The Appeal Process

  1. Request the reason for denial — The FBI will send you a letter explaining the basis for the denial if you request it. You can also call the NICS Appeals Services Team at 1-877-324-6427.

  2. Obtain your records — Request a copy of your criminal history from the FBI (through an Identity History Summary Request) and your state's Bureau of Investigation.

  3. Correct any errors — If the denial is based on incorrect information, work with the originating agency (court, state police, etc.) to correct the record.

  4. Submit a formal appeal — File an appeal with the NICS Section. Include documentation supporting your eligibility (court records showing dismissal, expungement orders, etc.).

  5. Wait for resolution — FBI appeals can take 30–90 days or longer depending on complexity.

  6. Consider a UPIN — If you experience recurring delays due to a common name, apply for a Unique Personal Identification Number (UPIN). This number is associated with your checked identity and helps the system distinguish you from similarly named prohibited persons.

UPIN: Your Solution for Recurring Delays

A UPIN is a unique number assigned by the FBI to individuals who have been delayed or denied due to mistaken identity. Once issued, you provide your UPIN on every 4473, and the system uses it to quickly verify your identity. Application is free through the FBI's Voluntary Appeal File (VAF) program.

State Variations

Some states have additional requirements beyond the federal NICS check:

  • Point of Contact (POC) states — The state conducts the check instead of the FBI, adding state-specific databases to the search (CA, CO, CT, FL, HI, IL, NV, NJ, OR, PA, TN, UT, VA, WA, and others)
  • Permit-based exemptions — In some states, a valid concealed carry permit serves as an alternative to the NICS check at point of sale (speeds up the process)
  • Waiting periods — Some states impose mandatory waiting periods regardless of NICS approval (CA: 10 days, FL: 3 days for handguns, etc.)
  • Additional state permits — Some states require state-issued purchase permits in addition to the NICS check (CT, IL, MA, NJ)

Check your state's specific requirements in our state gun law guides.

NICS Statistics

Since its inception in 1998, NICS has processed over 400 million background checks. Key statistics:

  • Average daily volume: 75,000–100,000 checks on normal days
  • Black Friday record: Over 200,000 checks in a single day (the busiest gun-buying day annually)
  • Denial rate: Approximately 1.5–2% of checks result in denial
  • Average check time: Under 2 minutes for electronic checks with no delays

Tips for a Smooth Background Check

  1. Bring valid government-issued photo ID — Current, not expired, with your correct legal name and address
  2. Know your Social Security Number — While optional on the 4473, providing your SSN dramatically reduces the chance of a mistaken-identity delay
  3. Use your legal name exactly as it appears on your ID
  4. If you have a common name — Consider getting a UPIN to avoid recurring delays
  5. Resolve any outstanding legal issues before attempting to purchase — an open warrant or pending case will result in a delay or denial
  6. Check your own criminal history before purchasing if you have any past contacts with the criminal justice system

Learn more about the purchase process in our guide to buying guns online and find FFL dealers near you in our dealer directory. Find great deals at your next gun show.