The legal requirements to make a suppressor start with a single rule: you must file ATF Form 1, pay the making tax, and receive written approval before you build anything. The National Firearms Act treats a homemade suppressor exactly like any other NFA firearm, and manufacturing one without an approved application is a federal felony carrying up to ten years in prison. The making tax for suppressors is currently $0 by statute, but every other step of the process remains in force.
What Federal Law Counts as a Suppressor
The National Firearms Act, codified at 26 U.S.C. Chapter 53, classifies a suppressor (the statute uses “silencer”) as a “firearm” alongside machineguns and short-barreled rifles.1Office of the Law Revision Counsel. 26 USC Chapter 53 – Machine Guns, Destructive Devices, and Certain Other Firearms The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) enforces the rules.
The definition is broad. Under 18 U.S.C. 921(a)(24), a suppressor includes any device designed to muffle or reduce the sound of a firearm, any combination of parts designed for assembling one, and any individual part intended solely for that purpose.2Legal Information Institute. 18 USC 921(a)(24) – Firearm Silencer Definition Even a single component clearly meant for a suppressor qualifies as one under federal law, assembled or not. This is why buying parts before your paperwork clears is dangerous, and it is why the Form 1 process matters even for a device you plan to make yourself out of raw materials.
How You File: Individual, Trust, or Entity
You can apply as an individual, through a gun trust, or through a legal entity like an LLC. The choice affects who can lawfully possess and handle the finished suppressor.
Filing as an individual means only you can possess and use it. Nobody else, including a spouse, can handle the suppressor outside your direct physical presence without committing a federal violation.3eCFR. 27 CFR Part 479 Subpart E – Tax on Making Firearms You submit your own fingerprints and photograph.
A gun trust lets multiple trustees possess and use the suppressor. Each “responsible person” on the trust must submit fingerprints, a photograph, and a completed ATF Form 5320.23 (Responsible Person Questionnaire). Trusts also spell out who inherits the item when the original maker dies.
An LLC or corporation works similarly to a trust: multiple responsible persons can be named, each going through the same background check, and the entity must document its legal existence. Trusts and entities take more upfront work, but shared possession is a real practical benefit.
The Form 1 Application
Every person making a suppressor files ATF Form 1 (Form 5320.1), “Application to Make and Register a Firearm.”4Bureau of Alcohol, Tobacco, Firearms, and Explosives. ATF Form 5320.1 Application to Make and Register NFA Firearm Manufacturing before approval is a federal crime, even if you fully intend to register the finished product.
Who Qualifies
The NFA does not set a minimum age for making a firearm, but the Gun Control Act generally requires you to be at least 18 to possess one. Buying an NFA item from a licensed dealer requires you to be 21. You are disqualified from making or possessing a suppressor if you have a felony conviction, a domestic violence misdemeanor conviction, a dishonorable discharge, an active restraining order, unlawful drug use in your history, or an adjudication of mental incompetence.4Bureau of Alcohol, Tobacco, Firearms, and Explosives. ATF Form 5320.1 Application to Make and Register NFA Firearm The ATF runs a NICS background check on every applicant.
The Making Tax
Under 26 U.S.C. 5821, the tax on making an NFA firearm is $200 for machineguns and destructive devices and $0 for all other NFA firearms, including suppressors.5Office of the Law Revision Counsel. 26 USC 5821 – Making Tax Some ATF regulations and older form instructions still reference the previous $200 amount. The statute controls, but if the eForms system still shows a $200 charge when you apply, contact the ATF to confirm the current fee before you submit.
CLEO Notification
Federal regulations at 27 C.F.R. 479.62(c) require you to send a copy of your completed Form 1 to the Chief Law Enforcement Officer in your area, typically the local chief of police, county sheriff, head of state police, or a local district attorney. If you file through a trust or entity, each responsible person sends their completed Form 5320.23 to their respective CLEO. The CLEO does not approve or deny anything. This is notification only. Once the paperwork is sent, your obligation is complete, and a tracked mailing method gives you proof of delivery.
Fingerprints and Photographs
Individual applicants submit two FBI fingerprint cards (Form FD-258) and a passport-style photograph with each application.6Bureau of Alcohol, Tobacco, Firearms and Explosives. NFA Form One Submission External Guidance – Chapter 3 E-Form 1 Fingerprint Options If you file electronically, you have 10 days from your eForms submission to mail the cards. For trusts and entities, every responsible person submits their own set.
Submitting and Waiting
You can submit Form 1 electronically through the ATF eForms system or on paper by mail.7Bureau of Alcohol, Tobacco, Firearms and Explosives. eForms Applications Electronic filing is strongly preferred. The ATF publishes current processing times that shift with application volume; check them before you plan any build timeline.8Bureau of Alcohol, Tobacco, Firearms and Explosives. Current Processing Times When your application is approved, the ATF affixes the NFA tax stamp and returns the approved copy. You cannot start building until that approved form is in your hands.4Bureau of Alcohol, Tobacco, Firearms, and Explosives. ATF Form 5320.1 Application to Make and Register NFA Firearm
Engraving the Finished Suppressor
Once your Form 1 is approved and you build the suppressor, you must permanently mark it. Under 27 CFR 479.102, the required markings are:9ATF eRegulations. 27 CFR 479.102 Identification of Firearms
- A unique serial number, matching what you listed on your Form 1, that does not duplicate any serial number on your other firearms.
- Your name, or a recognized abbreviation of it, as the maker.
- The city and state where you made the suppressor.
- The caliber or gauge the suppressor is designed for.
- A model designation, if you have assigned one.
Engravings must be at least 0.003 inches deep, and the serial number must be no smaller than 1/16 of an inch. Markings must use Roman letters and Arabic numerals and be placed where they resist easy removal or alteration. Most people hire an engraving service rather than attempt this at home. Professional engraving typically costs $25 to $125.
Solvent Traps and Loose Parts
A common and dangerous misconception is that buying a “solvent trap” or “fuel filter” kit gives you a head start on a legal suppressor build. The ATF addressed this directly in a 2023 open letter, stating that many devices marketed as solvent traps are silencers under federal law based on their design features.10Bureau of Alcohol, Tobacco, Firearms and Explosives. Open Letter to All Federal Firearms Licensees – Solvent Trap Devices Baffles, spacers, expansion chambers, end caps, and marks showing where to drill holes all point toward suppressor design rather than any legitimate solvent-catching purpose.
Because federal law defines a suppressor to include individual parts intended for assembly into one, possessing these components without an approved Form 1 can bring prosecution.2Legal Information Institute. 18 USC 921(a)(24) – Firearm Silencer Definition Federal courts have upheld convictions even when the device was not functional in its current state. The underlying legal concept is constructive possession: if you own parts with no plausible purpose other than building a suppressor and you have no tax stamp, prosecutors can treat that as possession of an unregistered NFA firearm. Do not acquire suppressor components, kits, or anything marketed as a solvent trap until your Form 1 is approved.
State Law Still Applies
Federal approval alone does not make your suppressor legal. Eight states currently ban civilian suppressor ownership outright, and no federal tax stamp overrides that prohibition. The remaining 42 states permit civilian ownership, though some impose additional conditions. Nine states also prohibit using suppressors while hunting, even where ownership is otherwise legal. State laws change, so verify possession and manufacturing legality in your state and local jurisdiction before filing your Form 1.
Rules That Continue After You Build
Approval, construction, and engraving do not end your legal obligations. Several ongoing requirements catch owners off guard.
You Cannot Sell It Freely
A suppressor made on a Form 1 is registered to you personally, or to your trust or entity. You cannot manufacture suppressors for sale without a Federal Firearms License (Type 07 or Type 10) and Class 2 Special Occupational Taxpayer registration. To transfer a Form 1 suppressor to another person, the recipient must file ATF Form 4 and go through the full approval process. Handing it off or selling it privately without ATF involvement is illegal.
Crossing State Lines
Transporting an NFA firearm across state lines requires prior written authorization from the ATF using Form 5320.20 (Application to Transport Interstate).11Bureau of Alcohol, Tobacco, Firearms and Explosives. Application to Transport Interstate or to Temporarily Export Certain National Firearms Act Firearms Submit it before you travel and receive approval for a specific time period. If a shipping carrier moves the item, a copy of the approved form must travel with it. Federal transport approval does not legalize possession in a state that bans suppressors; you remain subject to the law of every state you enter.
Storage
No federal regulation mandates a specific safe or lock, but you are legally responsible for preventing access by anyone not authorized to possess your suppressor. For individual registrations, that is everyone but you. For trusts, only named trustees. If an unauthorized person gains access, both you and that person face potential federal charges for unlawful possession of an unregistered NFA item.
Penalties
The list of prohibited acts under 26 U.S.C. 5861 includes making a suppressor without approval, possessing an unregistered one, receiving one that was made or transferred illegally, and altering or removing its serial number.12GovInfo. 26 USC 5861 – Prohibited Acts Each is a federal felony.
The NFA’s penalty provision at 26 U.S.C. 5871 sets punishment at a fine of up to $10,000, imprisonment of up to ten years, or both.13Office of the Law Revision Counsel. 26 USC 5871 – Penalties The general federal sentencing statute at 18 U.S.C. 3571 allows fines of up to $250,000 for any federal felony conviction, which can apply in addition to or in place of the NFA-specific amount.14Office of the Law Revision Counsel. 18 USC 3571 – Sentence of Fine
Any suppressor involved in an NFA violation is subject to seizure and forfeiture. Under 26 U.S.C. 5872, forfeited NFA firearms are either destroyed or transferred to a government agency, so you will not get it back.15Office of the Law Revision Counsel. 26 USC 5872 – Forfeitures A conviction also makes you a prohibited person under federal law, permanently barring you from possessing any firearm.