To legally sell a firearm suppressor, the buyer must file an ATF Form 4 transfer application, pass a federal background check, and receive written ATF approval before you hand over the suppressor. That rule is absolute. It does not matter how well you know the buyer, whether money has changed hands, or how short the drive is between you. Transfer possession before the approved Form 4 comes back and you have committed a federal felony carrying up to ten years in prison.1Office of the Law Revision Counsel. 26 USC 5871 – Penalties
The rest of the process depends on where the buyer lives, whether either of you uses a gun trust, and whether a licensed dealer needs to be involved.
Confirm You Can Actually Sell It
Start by locating your approved ATF Form 4 (or Form 1 if you built the suppressor yourself). The form with the affixed tax stamp is your proof that the suppressor is legally registered to you in the National Firearms Registration and Transfer Record. Without it, you cannot initiate a transfer.
Pull the suppressor’s serial number and manufacturer information at the same time. The buyer’s Form 4 has to describe the exact item, and having the details ready avoids delays once you find a buyer.
Then check state law. Forty-two states allow civilian suppressor ownership; eight do not. Both you and the buyer have to be in states that permit possession, and you cannot transport a suppressor into a prohibiting state to complete a sale. Some permissive states layer their own requirements on top of the federal rules, so read your own state’s law before listing.
Selling to Someone in Your Own State
Federal law does not require a licensed dealer for a suppressor transfer between two individuals in the same state. The ATF’s NFA Handbook confirms that Form 4 is the correct application for transfers between non-licensees.2Bureau of Alcohol, Tobacco, Firearms and Explosives. ATF NFA Handbook – Transfers of NFA Firearms
The buyer fills out and submits Form 4 directly to the ATF, listing you as the transferor. You keep the suppressor in your possession the entire time the application is pending. When approval comes back, you hand it over. Not before.
The upside is that you avoid a dealer’s transfer fee. The downside is that the timing discipline is entirely on you. There is no shop holding the item and no clerk to stop a premature handoff.
Selling to a Buyer in Another State
Interstate transfers of NFA firearms have to move through licensed dealers. Specifically, dealers with a Special Occupational Tax (SOT) classification, which authorizes them to handle NFA items.
The sequence:
- The buyer finds an SOT dealer in their state willing to receive the suppressor.
- You ship the suppressor to that dealer, typically through your own local SOT dealer, using an ATF Form 3. Form 3 is a tax-exempt dealer-to-dealer transfer, and eForm 3 applications currently process in about a day.3Bureau of Alcohol, Tobacco, Firearms and Explosives. Current Processing Times
- Once the suppressor arrives at the receiving dealer, the buyer files Form 4 with the ATF.
- After Form 4 approval, the buyer picks up the suppressor from the dealer.
The receiving dealer charges a transfer fee for holding the item and processing the pickup. Fees vary by shop, so the buyer should confirm the number before choosing where to have it sent.
If the Suppressor Is Held in a Gun Trust
When a trust owns the suppressor, the trust is the registered owner, not you personally. You can still sell it, but two things change.
First, the trustee with authority to dispose of trust assets is the one who signs as transferor on the Form 4. Read your trust document and confirm that whoever is handling the sale actually has that authority.
Second, if the buyer is also acquiring through a trust or legal entity, every “responsible person” on the buyer’s side must individually complete ATF Form 5320.23, the Responsible Person Questionnaire, along with fingerprints and a passport-style photograph.4Bureau of Alcohol, Tobacco, Firearms and Explosives. National Firearms Act (NFA) Responsible Person Questionnaire – ATF Form 5320.23 A copy of each questionnaire also goes to that person’s local Chief Law Enforcement Officer. Five responsible persons on the buyer’s trust means five sets of paperwork.
Who the Buyer Has to Be
The ATF will not approve a transfer to a buyer who is federally prohibited from possessing firearms. The buyer must also be a U.S. resident and live in a state that permits suppressor ownership. Age minimums are 21 to buy from a dealer and 18 to acquire from an individual, though state law can raise the floor.
Approval times through the eForms system have improved substantially. As of early 2026, individual eForm 4 applications have a median approval time of roughly 4 to 10 days, and trust applications run around 24 to 26 days.3Bureau of Alcohol, Tobacco, Firearms and Explosives. Current Processing Times Both are dramatically shorter than the eight-to-ten-month waits typical of paper filings.
Handing Over the Suppressor
When the approved Form 4 comes back with the tax stamp affixed, the transfer can complete. For a dealer transfer, the buyer visits the shop and fills out an ATF Form 4473.5Bureau of Alcohol, Tobacco, Firearms and Explosives. ATF Form 4473 – Firearms Transaction Record Revisions Because the ATF already ran a background check as part of Form 4 processing, the dealer does not need to run a separate NICS check at pickup. For a private in-state sale, there is no Form 4473 at all. The buyer shows you the approved Form 4 and you release the suppressor.
Your original approved Form 4, the one that registered the suppressor to you, no longer authorizes possession once the transfer is complete. The ATF’s registry now shows the new owner. Keep your copy for your records anyway, but understand its legal effect has ended.
The $200 Tax Is Gone, but the Process Isn’t
Congress passed H.R. 1 in 2025, and as of January 1, 2026, the transfer tax on suppressors is $0. The $200 tax still applies to machineguns and destructive devices, but suppressors are out.6Office of the Law Revision Counsel. 26 USC 5811 – Transfer Tax
Nothing else changed. Every suppressor still has to be registered, every transfer still needs an approved Form 4, and every buyer still has to pass the ATF’s background check.7Office of the Law Revision Counsel. 26 USC 5812 – Transfers Fingerprints, photos, and waiting periods are unchanged. What used to be a $200 stamp is now a $0 stamp, but it is still a stamp.
What Happens If You Skip the Process
Transferring a suppressor without ATF approval is not a technicality. Under 26 USC 5871, an unlawful transfer carries up to ten years in prison and a fine of up to $10,000.1Office of the Law Revision Counsel. 26 USC 5871 – Penalties That exposure attaches to a seller who releases the suppressor early just as much as to anyone who arranges an unregistered sale.
The safe path is also the simple one. File the correct form, wait for the approval to arrive in writing, and only then let the suppressor leave your hands.