ATF NFA Forms Explained: Form 1, Form 4, Form 5, and 5320.20

The four ATF forms that most NFA owners deal with each handle a different moment in the life of a regulated firearm: Form 1 to make one yourself, Form 4 to buy one, Form 5 to transfer one tax-free (most often to an heir), and Form 5320.20 to move certain items across state lines. Here is what each ATF NFA form does, what it requires, and what changed on January 1, 2026, when Public Law 119-21 dropped the federal tax on making or transferring suppressors, short-barreled rifles, short-barreled shotguns, and “any other weapons” from $200 (or $5 for AOWs) to $0. Machine guns and destructive devices still carry the $200 tax. The registration process, background checks, and wait times all remain in place.¹² Skipping any part of the registration system still carries penalties up to $250,000 and ten years in federal prison.³

Which Firearms Require These Forms

Federal law defines an NFA “firearm” as an item in one of six categories:⁴

Short-barreled rifles (SBRs): rifles with barrels under 16 inches, or overall length under 26 inches.
Short-barreled shotguns (SBSs): shotguns with barrels under 18 inches, or overall length under 26 inches.
Machine guns: any weapon that fires more than one round per trigger pull, plus the parts designed to convert a weapon into one.
Suppressors (silencers): devices designed to muffle a firearm’s sound.
Destructive devices: explosives, grenades, rockets, and firearms with a bore over half an inch (with some sporting exceptions).
Any other weapons (AOWs): a catch-all for concealable weapons that don’t fit the other categories, like pen guns and smooth-bore pistols.

Every one of these must be listed in the ATF’s National Firearms Registration and Transfer Record. If an item isn’t in that registry, possessing it is a federal felony.⁵ The four forms below are how you get and stay on the right side of it.

Form 1: Making an NFA Firearm

File Form 1, the “Application to Make and Register a Firearm,” when you plan to build an NFA item yourself. That includes assembling a suppressor from a kit, cutting down a rifle barrel below 16 inches, or converting a pistol into an SBR with a stock. Federal law requires the form to be submitted and approved before you start any work.⁶ Building first and applying later is a felony even if the intent was always to register.

The making tax is $0 for suppressors, SBRs, SBSs, and AOWs. It remains $200 for machine guns and destructive devices, which civilians generally cannot make lawfully in any event.²

Engraving Requirements

Once Form 1 is approved, you are the “maker” and must permanently mark the firearm before or during assembly. The markings go on the frame or receiver and include your name, the city and state of manufacture, a unique serial number, and the caliber or gauge. A model name goes on if you’ve designated one. Markings must be engraved, cast, or stamped at least .003 inches deep, and the serial number must be at least 1/16 inch tall.⁷ Professional engraving typically runs $20 to $125. Doing it yourself with a rotary or electric hand engraver is allowed, so long as depth and size meet the minimums.

Form 4: Buying an NFA Item

Form 4, the “Application for Tax Paid Transfer and Registration of Firearm,” is the standard form for buying an existing NFA item from a dealer or a private seller. It moves the item into your name on the registry. The transfer tax is $0 for suppressors, SBRs, SBSs, and AOWs, and $200 for machine guns and destructive devices.¹

Both the seller and buyer are named on the form. An individual buyer must also submit fingerprints and a photograph. The ATF will deny any transfer that would put the buyer in violation of law.⁸ You cannot take possession until the approved form comes back. The dealer holds the item until then.

The Machine Gun Ceiling

Form 4 technically covers machine gun purchases, but the supply is frozen. Federal law bans civilian possession of any machine gun not already lawfully registered before May 19, 1986.⁹ Only pre-1986 transferable machine guns can be bought and sold by civilians. A transferable M16 or MP5 routinely sells for $30,000 or more, and the $200 tax is the smallest part of the cost.

Form 5: Tax-Exempt Transfers and Inheritance

Form 5, the “Application for Tax-Exempt Transfer and Registration of Firearm,” covers two situations that carry no tax: transfers to or from government agencies, and transfers to lawful heirs after a registered owner dies.¹⁰

Inheritance is the one most families run into. When a registered NFA owner dies, the estate’s executor uses Form 5 to transfer the items to whoever is named in the will or entitled to them under state law. This exemption predated the 2026 tax changes and applies to all NFA categories, including machine guns and destructive devices. The heir still goes through the same background check and identification process as any other applicant. The exemption is from the tax, not from the vetting.

While the Form 5 is pending, the items should stay with the executor or a licensed dealer. An heir who takes possession before approval is in unlawful possession of an unregistered NFA firearm, no matter what the will says.

Form 5320.20: Interstate Transport

Form 5320.20, the “Application to Transport Interstate or to Temporarily Export Certain NFA Firearms,” is required before you move a machine gun, SBR, SBS, or destructive device across state lines. Anyone other than a licensed dealer, manufacturer, or importer needs prior ATF authorization to transport these items in interstate commerce.¹¹

Suppressors and AOWs do not require Form 5320.20 for interstate travel. If a suppressor is legal in both the origin and destination states, you can transport it without filing. But driving an SBR to a competition in another state, even for a weekend, requires ATF approval in hand before you cross the state line.

The form asks for the reason for transport, the specific dates, and the origin and destination addresses. Once approved, the authorization covers the listed serial number for the dates and locations specified. A permanent move requires a new filing rather than an extension. Crossing state borders without an approved 5320.20 for a covered item can lead to seizure and federal charges.

Filing as an Individual or Through a Trust

Any of these forms can be filed by an individual or through a gun trust or other legal entity. The main practical reason to use a trust is shared access: any trustee named on the approved form can legally possess and use the trust’s NFA items. An individually registered item can only be possessed by that individual, which creates a problem the moment a spouse or family member needs to handle it.¹² Trusts also simplify inheritance, since the items pass to the successor trustee or beneficiaries under the trust document rather than through the Form 5 probate route.

The tradeoff is Form 5320.23, the Responsible Person Questionnaire. Since July 2016, every responsible person in a trust or legal entity must submit this form with each NFA application. That means fingerprint cards and a passport-style photograph for every trustee, not just the buyer.¹³ A responsible person is anyone with authority to direct the trust or to possess, transport, or transfer NFA items on its behalf. That usually covers grantors and trustees, and sometimes beneficiaries who have been given those powers. A beneficiary who simply receives items upon the grantor’s death is generally excluded.¹² Each responsible person also has to send a copy of the completed 5320.23 to their local chief law enforcement officer.

CLEO Notification

Every NFA applicant, individual or trust, must notify a chief law enforcement officer before submitting to the ATF. This replaced the older system that required the CLEO to sign off on the application, which gave local officials a veto. Since July 2016, notification is enough. The CLEO doesn’t need to approve anything.¹⁴

Your CLEO is the chief of police, county sheriff, head of state police, or local district attorney with jurisdiction where you live. Individual applicants send a copy of the completed Form 1 or Form 4. Trust applicants send copies of Form 5320.23 for each responsible person. There’s no waiting for a response. Send the notification before or at the same time you submit to the ATF.

How To Submit and How Long It Takes

You can file NFA applications either on paper or through the ATF’s eForms portal. eForms is faster in most cases and lets you upload documents, attach digital fingerprint files, and pay electronically. Paper applications go by mail to the ATF’s National Firearms Registration and Transfer Center in Martinsburg, West Virginia, with physical fingerprint cards, photographs, and payment.

Whatever form you file, expect to provide your full legal name, home address, and Social Security number, plus firearm details: manufacturer, model, caliber or gauge, serial number, and where applicable, barrel length and overall length. Individual applicants include two passport-style photographs (2×2 inches, taken within the past year) and two FBI FD-258 fingerprint cards.⁶⁸ Fingerprints can be submitted as electronic .EFT files through eForms instead of physical cards.¹⁵

After submission the application enters pending status while the FBI runs the background check. You cannot take possession of a transferred item or begin building until the approved form comes back. Approval is issued as a stamp, physical or digital, that serves as permanent proof of registration. Keep copies in a secure location separate from the firearm, and have them accessible during any law enforcement encounter involving the item.

Current ATF processing estimates:¹⁶

Form 1 (eForms): about 36 days
Form 1 (paper): about 20 days
Form 4 individual (eForms): about 10 days
Form 4 trust (eForms): about 26 days
Form 4 (paper): about 21–24 days

These numbers shift with application volume. The elimination of the $200 tax could drive a surge, so check the ATF’s processing times page before you file.

State Law Still Applies

Federal registration does not override state or local law. Some states ban or restrict specific NFA categories: certain states prohibit suppressors, others ban SBRs, and a handful bar private machine gun ownership entirely. An approved ATF form and a valid tax stamp mean nothing if the item is illegal where you live or travel.¹⁷ The reverse holds too: state legality doesn’t get you a pass on federal registration. You need both. Confirm state law at both ends of any interstate trip before you rely on a Form 5320.20 approval, because that approval doesn’t guarantee the destination state allows the item.

1
Office of the Law Revision Counsel. 26 USC 5811 – Transfer Tax
2
Office of the Law Revision Counsel. 26 USC 5821 – Making Tax
3
Bureau of Alcohol, Tobacco, Firearms and Explosives. NFA Handbook Chapter 15 – Penalties and Sanctions
4
Office of the Law Revision Counsel. 26 USC 5845 – Definitions
5
Bureau of Alcohol, Tobacco, Firearms and Explosives. National Firearms Act
6
Office of the Law Revision Counsel. 26 USC 5822 – Making
7
eCFR. 27 CFR 479.102 – How Must Firearms Be Identified?
8
Office of the Law Revision Counsel. 26 USC 5812 – Transfers
9
Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts
10
eCFR. 27 CFR 479.90 – Certain Government Entities
11
Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts
12
Bureau of Alcohol, Tobacco, Firearms and Explosives. Background Checks for Responsible Persons (Final Rule 41F)
13
Bureau of Alcohol, Tobacco, Firearms and Explosives. ATF Form 5320.23 – Responsible Person Questionnaire
14
Bureau of Alcohol, Tobacco, Firearms and Explosives. Firearms – Frequently Asked Questions
15
Bureau of Alcohol, Tobacco, Firearms and Explosives. NFA Form 1 Submission External Guidance
16
Bureau of Alcohol, Tobacco, Firearms and Explosives. Current Processing Times
17
Bureau of Alcohol, Tobacco, Firearms and Explosives. 27 CFR Part 479 – Machine Guns, Destructive Devices, and Certain Other Firearms