"Under the ATF's October 9, 2026 guidance, a private, face-to-face sale of a suppressor between two eligible Arizona residents generally does not require an ATF Form 4 or a Form 4473.
The key distinction is that Form 4473 is required for transfers by federally licensed firearms dealers (FFLs), not ordinarily for a genuinely private sale between two unlicensed individuals. The ATF's new guidance says unlicensed individuals no longer need prior NFA approval to transfer covered suppressors, while the Gun Control Act's other requirements remain in effect.
Conditions to keep in mind. Both parties should be Arizona residents. The ATF says an unlicensed individual may not transfer these items to a resident of another state. The buyer must be legally eligible to possess firearms. Federal and Arizona restrictions still apply.
Because this is a very recent change, keeping a simple bill of sale with both parties' names, the suppressor's make, model and serial number, and the date would be prudent, even though that is not the same as a required Form 4473.
Bottom line: For a private sale between two eligible Arizona residents, the new ATF guidance indicates that neither a Form 4 nor a Form 4473 is federally required. The Form 4473 requirement applies when an FFL handles the transfer."
From the ATF Letter dated October 9, 2026
..........ATF will no longer require individuals to seek ATF approval under the NFA
before making or transferring short-barreled rifles, short-barreled shotguns, silencers, and “any
other weapon[s]” as defined in 26 U.S.C. § 5845(e). ATF will also no longer require such items
to be registered in the National Firearms Registration and Transfer Record.......
This is not legal advice, just an observation.