To buy a gun from a licensed dealer, you need to be old enough for the type of firearm you want (18 for long guns, 21 for handguns under federal law), bring a valid government-issued photo ID, fill out ATF Form 4473 truthfully, and pass a background check through the FBI’s National Instant Criminal Background Check System. Everything else about how to buy a gun (waiting periods, private sales, buying across state lines, or purchasing regulated items like suppressors) layers on top of those basics and varies by state and firearm type.
Are You Eligible to Buy
Federal law sets two age floors at licensed dealers: 18 for rifles and shotguns, 21 for handguns.1Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts Some states raise those minimums, so check your state’s rule before you go.
Federal law also blocks several categories of people from buying or possessing firearms at all. You cannot legally buy a gun if you have a felony conviction (any crime punishable by more than a year in prison, regardless of the sentence you actually served), an active warrant, a current unlawful drug habit, a qualifying mental-health commitment or adjudication, a dishonorable discharge, or a misdemeanor domestic violence conviction. The same bar applies if you’re subject to a qualifying domestic protective order, if you’ve renounced U.S. citizenship, or if you’re in the country unlawfully or on most nonimmigrant visas.2Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts
The background check is designed to catch these disqualifiers, but the prohibition exists whether or not the system flags it. If a bar applies to you and you attempt to buy anyway, you commit a federal crime the moment you sign the paperwork.
What to Bring
Bring a current, unexpired government-issued photo ID that shows your name, date of birth, and residential address. A driver’s license or state ID card is the usual choice.3Bureau of Alcohol, Tobacco, Firearms and Explosives. Firearms Transaction Record – ATF Form 4473
If the address on your ID doesn’t match where you live now, bring a second government-issued document showing your current address, such as a vehicle registration or voter registration card. The supplemental document has to be government-issued; a utility bill won’t do it.3Bureau of Alcohol, Tobacco, Firearms and Explosives. Firearms Transaction Record – ATF Form 4473
Form 4473 and the Background Check
At the counter, the dealer hands you ATF Form 4473, the Firearms Transaction Record. You fill in your personal information and answer a series of yes-or-no questions covering each prohibited category. The dealer cannot complete the form for you, and every answer is given under penalty of perjury.3Bureau of Alcohol, Tobacco, Firearms and Explosives. Firearms Transaction Record – ATF Form 4473
Once the form is done, the dealer contacts NICS. You’ll get one of three responses:4FBI. About NICS
- Proceed. You passed. The dealer can complete the sale, unless your state imposes its own waiting period.
- Denied. The system found a disqualifying record and the dealer cannot transfer the firearm.
- Delayed. The FBI needs more time to sort out something on your record.
There is no federal waiting period beyond the check itself. If you get a “proceed,” federal law lets the dealer hand you the firearm that same visit. Roughly a dozen states impose their own mandatory waiting periods (from a few days to about two weeks) regardless of how fast the check clears.
The Three-Business-Day Rule
When a check comes back delayed, the FBI has three business days to make a final call. If those three days pass without a denial, the dealer is legally allowed to complete the transfer.1Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts The dealer isn’t required to; many shops still wait for a definitive answer, and some states prohibit transfer until the check is fully resolved.
If You’re 18, 19, or 20
Since 2022, buyers between 18 and 20 face expanded background checks under the Bipartisan Safer Communities Act. NICS also contacts state juvenile justice records, mental health adjudication records, and local law enforcement to look for disqualifying juvenile history.1Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts
That takes longer. If the system finds something worth investigating, the FBI can delay the transfer for up to 10 business days from the dealer’s initial contact, compared to the three-day window for buyers 21 and older.5Federal Register. Bipartisan Safer Communities Act of 2022 – Implementation Don’t count on a same-day pickup for your first purchase in that age range.
If You’re Denied or Delayed
False hits happen. A similar name or an outdated record can trigger a denial for someone who is legally eligible. To appeal, you’ll need your full name, mailing address, and the NICS Transaction Number or State Transaction Number from the denied transaction. Submit these to the FBI or the state agency that ran the check. The FBI will give you the general reason for the denial within five business days, though confirming the specific record on you requires fingerprint verification.6FBI. NICS Guide for Appealing
If you keep getting wrongly denied or delayed, the FBI runs a Voluntary Appeal File. Once approved, you get a Unique Personal Identification Number to write on future Form 4473s so the system can tell you apart from whichever record is causing the trouble. Applying is free, but you’ll need to submit a fingerprint card.7FBI. Voluntary Appeal File
Buying From a Private Seller
Federal law lets two people who live in the same state buy and sell firearms between themselves without going through a dealer and without a NICS check. The seller can’t have reason to believe the buyer is prohibited.8Bureau of Alcohol, Tobacco, Firearms and Explosives. Best Practices – Transfers of Firearms by Private Sellers No federal paperwork is required.
State law is where this changes. Roughly 17 states and the District of Columbia require private sales to go through a licensed dealer who runs a background check on the buyer. If you’re on either side of a private sale, check your state’s rules first.
Buying From Someone in Another State
Federal law prohibits an unlicensed person from transferring a firearm to someone they know or reasonably believe lives in a different state.1Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts Any sale between residents of different states has to go through a licensed dealer. The seller ships the firearm to a dealer in your state, you complete Form 4473 there, pass the background check, and take possession from that dealer. Expect a transfer fee somewhere between $20 and $75.
Suppressors, Short-Barreled Rifles, and Other NFA Items
The National Firearms Act covers a specific class of weapons that require federal registration on top of a standard purchase: machine guns, rifles with barrels shorter than 16 inches, shotguns with barrels shorter than 18 inches, suppressors, destructive devices, and a residual category the law labels “any other weapons.”9Office of the Law Revision Counsel. 26 USC 5845 – Definitions
Buying an NFA item means filing a registration form with the ATF, submitting photographs and fingerprints, and going through an additional background check separate from the standard NICS process. Approval times have historically run from weeks to many months. As of January 2026, the long-standing $200 federal transfer tax has been eliminated, so the fee for items like suppressors and short-barreled rifles is $0.10Bureau of Alcohol, Tobacco, Firearms and Explosives. National Firearms Act
Federal legality doesn’t cover state legality. Several states ban specific NFA items outright, especially machine guns and suppressors, and a handful prohibit all NFA items. Confirm your state and local rules before starting the paperwork.
What Gets People Prosecuted
Two mistakes account for most federal firearms purchase prosecutions.
The first is lying on Form 4473. Every question corresponds to a legal disqualifier, and answering any of them dishonestly is a standalone federal felony carrying up to 10 years in prison. Prosecutors pursue these cases even when no other crime accompanied the false statement.11Bureau of Alcohol, Tobacco, Firearms and Explosives. Federal Prosecutors Aggressively Pursuing Those Who Lie in Connection With Firearm Transactions
The second is a straw purchase: buying a firearm on behalf of someone else, usually to help them dodge a background check or avoid the paper trail. The baseline penalty is up to 15 years in prison, and up to 25 years if the firearm was intended for a felony, terrorism offense, or drug trafficking.12Office of the Law Revision Counsel. 18 USC 932 – Straw Purchasing of Firearms Buying a gun as a genuine gift for someone who is legally eligible to own one isn’t a straw purchase. The line is whether the actual recipient could lawfully buy it themselves and whether you’re stepping in to sidestep the check. When in doubt, let the intended owner make the purchase directly.