You can send most gun parts in the mail without any special license, paperwork, or carrier agreement. Barrels, triggers, stocks, handguards, springs, sights, and similar components are not classified as firearms under federal law, so they ship like any other product.1Office of the Law Revision Counsel. 18 USC 921 – Definitions The one part that changes everything is the frame or receiver, which federal law treats as the firearm itself. Once that is in the box, the same rules that govern shipping a complete rifle or handgun apply.
The Legal Line Between a Part and a Firearm
Under 18 U.S.C. § 921, “firearm” is not limited to a working weapon. The definition also covers the frame or receiver of any weapon, any silencer, and any destructive device.1Office of the Law Revision Counsel. 18 USC 921 – Definitions The frame or receiver is the serialized core that other components attach to. Alone on a shelf, with no barrel and no trigger group, it is still legally a firearm.
That single classification decides how your package moves. A replacement spring kit, a set of grips, or a new barrel travels under standard shipping rules. A stripped AR-15 lower receiver travels under the rules for a complete firearm. Everything below flows from this distinction.
Mailing Ordinary Gun Parts
Barrels, stocks, handguards, trigger assemblies, firing pins, sights, and magazines are not firearms under federal law, and an individual can ship them through USPS, UPS, or FedEx without a federal firearms license. UPS defines a “Firearm Part” as any component that does not by itself meet the definition of a firearm and accepts these for shipment, with the caveat that the parts in a single package cannot together be assembled into a functioning firearm.2UPS. How To Ship Firearms
No background check applies. No FFL transfer is needed. The seller drops the item in a box and it moves like any other online order.
State law adds a wrinkle worth checking before you mail. More than a dozen states restrict or ban magazines above a certain capacity, with limits ranging from 10 to 17 rounds depending on the jurisdiction. Sending a magazine that is legal where you live into a state that bans it can create liability for both the sender and the recipient, even though federal law does not prohibit the magazine. Verify the destination state’s rules before shipping accessories that might be restricted locally.
Mailing a Frame, Receiver, or Complete Firearm
Because a frame or receiver is legally a firearm, mailing one triggers the same federal restrictions as mailing a fully assembled rifle or handgun. The controlling statute is 18 U.S.C. § 922, which governs how firearms move in interstate commerce.
What an Individual Can and Cannot Do
Federal law explicitly allows an individual to mail a firearm they own to a licensed importer, manufacturer, dealer, or collector, provided the firearm complies with federal, state, and local law.3Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts This is the standard path for repair and customization work: you mail the firearm directly to an FFL gunsmith. When the work is done, the FFL can return it to you without a Form 4473 or a background check on the return trip.4Bureau of Alcohol, Tobacco, Firearms and Explosives. Federal Firearms Licensee Quick Reference and Best Practices Guide ATF Publication 5300.15
What an individual cannot do is ship a firearm across state lines to another private individual. If you sell a firearm to a buyer in another state, it must go through a licensed dealer. The buyer’s FFL receives the firearm, runs the background check, and processes the transfer. Transfer fees typically run $20 to $100 depending on the dealer.
NFA Items Need Approval First
Short-barreled rifles, short-barreled shotguns, machine guns, and destructive devices fall under the National Firearms Act and need written ATF approval before they cross state lines. The owner files ATF Form 5320.20 and waits for authorization before shipping.5Bureau of Alcohol, Tobacco, Firearms and Explosives. Application to Transport Interstate or to Temporarily Export Certain National Firearms Act (NFA) Firearms – ATF Form 5320.20 Skipping this step is a separate federal offense on top of any other shipping violations.
Carrier Rules
Federal law sets the floor. Each carrier adds its own layer. The rules below apply when a firearm, frame, or receiver is in the package. Ordinary parts ship under each carrier’s standard policies.
USPS
Handguns and other concealable firearms are nonmailable for ordinary individuals. Only specific parties listed in postal regulations, including FFLs, law enforcement, and certain government officials, may mail concealable firearms.6Postal Explorer. Publication 52 – Hazardous, Restricted, and Perishable Mail – Section 432 Mailability
Unloaded rifles and shotguns are mailable by individuals. USPS may ask for confirmation that the firearm is unloaded, either by opening the package or through a written certification. An individual mailing a long gun to themselves in another state (for a hunting trip, for example) must address it to themselves with an “in care of” endorsement listing whoever will hold the package until arrival, and the owner must be the one to open it. Mailable firearms have to move by Priority Mail Express with signature confirmation, or by Registered Mail.6Postal Explorer. Publication 52 – Hazardous, Restricted, and Perishable Mail – Section 432 Mailability
UPS
UPS accepts firearms only from FFL holders who have signed a UPS firearms agreement and set up a dedicated shipping account. Individuals generally cannot ship firearms through UPS.2UPS. How To Ship Firearms
Handguns must travel via one of UPS’s Next Day Air services. Every firearms package requires Delivery Confirmation Adult Signature Required and Direct Delivery Only, and the shipper must affix a UPS label requesting an adult signature. Ammunition must ship in a separate package from any firearm.
For non-firearm parts, UPS is more permissive: individuals can ship them without an FFL or special agreement, as long as the parts in the package cannot together be assembled into a complete firearm.
FedEx
FedEx limits firearm shipments to FFL holders and government agencies. FFLs must sign a FedEx Firearms Shipping Compliance Agreement before shipping any firearm. All firearms must be unloaded, every shipment requires an adult signature, and the outer packaging cannot display any markings indicating the contents. FedEx does not accept handguns via FedEx Ground.
One trap for shippers: FedEx’s declared-value coverage excludes firearms. If a firearm shipment is lost or damaged, FedEx will not reimburse the declared value.7FedEx. Declared Value and Limits of Liability for Shipments UPS has similar limits written into its terms. Third-party firearms insurance is the only reliable way to protect a high-value gun in transit.
Non-firearm parts ship under standard FedEx policies with no compliance agreement required.
Unfinished Frames and Build Kits
Items once sold as “80% receivers” or “buy build shoot” kits no longer live in a gray zone. Under ATF Final Rule 2021R-05F, effective August 24, 2022, a partially complete frame or receiver sold with jigs, templates, or tools that allow it to be readily finished is classified as a firearm.8Bureau of Alcohol, Tobacco, Firearms and Explosives. Final Rule 2021R-05F – Definition of Frame or Receiver and Identification of Firearms Overview Many kits that once shipped without serialization now fall under the same federal rules as a completed frame.
Raw material that has not reached a recognizable stage of manufacture is still unregulated. A blank block of aluminum or a piece of unformed polymer is not a firearm. The cutoff is whether the item is clearly identifiable as an unfinished component of a weapon and is paired with items that make completion straightforward.9Bureau of Alcohol, Tobacco, Firearms and Explosives. Training Aid for the Definition of Frame or Receiver and Identification of Firearms
A separate change applies to privately made firearms, sometimes called ghost guns. Federal law does not require individuals to serialize firearms they build for themselves. But any FFL who takes a PMF into inventory, whether for sale, consignment, or repair, must mark it with a unique serial number within seven days of receipt or before transferring it, whichever comes first.10Bureau of Alcohol, Tobacco, Firearms and Explosives. Privately Made Firearms Ship an unserialized PMF to a gunsmith and expect it back with a serial number.
Ammunition Is a Separate Problem
Ammunition does not follow firearm-parts rules, and it does not follow firearm rules either. USPS prohibits all small arms ammunition, primers, blank cartridges, and propellant powder from the mail. The ban applies to domestic and international shipments, with no exception for FFLs or law enforcement.11United States Postal Inspection Service. Hazardous Materials Regulations
UPS and FedEx accept ammunition, but only by ground service and only with proper hazardous-materials packaging. DOT classifies small arms cartridges as Division 1.4S explosives, which qualifies them for limited-quantity ground shipping when packaged correctly. Each package must stay under 66 pounds gross weight, primers must be protected from accidental initiation, and interior partitions or clips must hold the rounds snugly.12eCFR. 49 CFR 173.63 – Packaging Exceptions UPS requires ammunition to ship in a package separate from any firearm.
How To Package and Label the Box
Federal law requires anyone shipping a firearm or ammunition through a common carrier to give the carrier written notice that the package contains a firearm. At the same time, the law forbids the carrier from placing any external label, tag, or marking indicating the contents.3Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts The carrier knows what it is moving; the box does not advertise it to anyone who touches it along the way.
Use a plain, sturdy outer box with no manufacturer logos, brand names, or images that hint at the contents. Firearms should be unloaded and secured inside a hard case or wrapped in protective material so they cannot shift in transit. Cushion the interior with foam or packing material dense enough to stop rattling. For smaller parts like triggers or sights, inner boxes or sealed bags keep everything organized and protected.
Plain packaging is a smart practice for ordinary gun parts too, even though federal law does not require it. A box that obviously contains gun components is a theft target somewhere in the shipping chain.
Shipping Outside the United States
Sending gun parts overseas is not just an international shipping option in a checkout menu. Firearms, frames, receivers, and many components are classified as defense articles on the U.S. Munitions List, controlled under the International Traffic in Arms Regulations. Exporting any defense article requires prior approval from the State Department’s Directorate of Defense Trade Controls before the item leaves the country.13eCFR. 22 CFR Part 123 – Licenses for the Export and Temporary Import of Defense Articles
Penalties for unauthorized export are heavy. Criminal penalties under the Arms Export Control Act reach up to $1,000,000 in fines and 20 years in prison per violation.14Office of the Law Revision Counsel. 22 U.S. Code 2778 – Control of Arms Exports and Imports Civil penalties can reach the greater of $1,200,000 or twice the value of the transaction per violation. Even a barrel or a scope mount can fall under export controls if it is designed for military application.
What Happens If You Get It Wrong
Penalties scale with the violation:
- Knowingly depositing a handgun or other concealable firearm in the mail when you are not authorized to do so carries a fine and up to two years in federal prison.15Office of the Law Revision Counsel. 18 U.S. Code 1715 – Firearms as Nonmailable; Regulations
- Willful violations of shipping restrictions, including shipping a firearm interstate without a license or failing to give the carrier written notice, carry a fine and up to five years in prison.16Office of the Law Revision Counsel. 18 U.S. Code 924 – Penalties
- Knowingly transporting a firearm or ammunition in interstate commerce with intent to use it in a crime punishable by more than a year in prison carries up to ten years.17Office of the Law Revision Counsel. 18 USC 924 – Penalties
Beyond criminal exposure, carriers will close your account and refuse future shipments. UPS and FedEx both reserve the right to open and inspect packages they suspect contain improperly shipped firearms, and any violation of their terms forfeits declared-value protection. The tracking number creates a paper trail that leads directly back to the shipper, which is why these cases are straightforward for prosecutors.