Contents Index
C000 General Information

C020 Restricted or Nonmailable Articles and Substances

C024 Other Restricted or Nonmailable Matter


C024 describes other restricted or nonmailable items (e.g., firearms, sharp instruments, controlled substances, pesticides).

1.0 Pistols, Revolvers, and Other Concealable Firearms


The terms used in this standard are defined as follows:

a. Handgun means any pistol, revolver, or other firearm or device the mailing of which is regulated by this standard.

b. Pistol or revolver means a handgun styled to be fired by the use of a single hand and to fire or otherwise expel a projectile by the action of an explosion, spring, or other mechanical action, or air or gas pressure with enough force to be used as a weapon.

c. Firearm means any device, including a starter gun, designed to, or that may readily be converted to, expel a projectile by the action of an explosion, spring, or other mechanical action, or air or gas pressure with enough force to be used as a weapon.

d. Other firearms capable of being concealed on the person include, but are not limited to, short-barreled shotguns and short-barreled rifles.

e. Short-barreled shotgun means a shotgun that has one or more barrels less than 18 inches long. The term short-barreled rifle means a rifle that has one or more barrels less than 16 inches long. These definitions include any weapon made from a shotgun or rifle, whether by alteration, modification, or otherwise, if such weapon as modified has an overall length of less than 26 inches. A short-barreled shotgun or rifle of greater dimension may be regarded as nonmailable when it has characteristics to allow concealment on the person.

f. Licensed manufacturer and licensed dealer mean, respectively, a manufacturer of firearms or a bona fide dealer of firearms, duly licensed by the Bureau of Alcohol, Tobacco and Firearms of the Department of the Treasury, under the Gun Control Act of 1968 (Public Law 90-618), 18 USC 921, et seq.

g. Antique firearm means any firearm (including those with a matchlock, flintlock, percussion cap, or similar type of ignition system) manufactured in or before 1898, or any replica thereof, if such replica:

(1) Is not designed or redesigned for using rimfire or conventional centerfire fixed ammunition.

(2) Uses rimfire or conventional centerfire fixed ammunition that is no longer manufactured in the United States and that is not readily available in the ordinary channels of commercial trade.


Pistols, revolvers, and other firearms capable of being concealed on the person (referred to as handguns) are nonmailable unless mailed between the parties listed in 1.3 and 1.5 after the filing of an affidavit or statement required by 1.4 and 1.6.

1.3Authorized Persons

Subject to 1.4, handguns may be mailed by a licensed manufacturer of firearms, a licensed dealer of firearms, or an authorized agent of the federal government or the government of a state, territory, or district, only when addressed to a person in one of the following categories for use in the person’s official duties:

a. Officers of the Army, Coast Guard, Air Force, Navy, Marine Corps, or Organized Reserve Corps.

b. Officers of the National Guard or militia of a state, territory, or district.

c. Officers of the United States or of a state, territory, or district, whose official duty is to serve warrants of arrest or commitment.

d. USPS employees authorized by the Chief Postal Inspector.

e. Officers and employees of enforcement agencies of the United States.

f. Watchmen engaged in guarding the property of the United States, a state, territory, or district.

g. Purchasing agent or other designated member of agencies employing officers and employees included in 1.3c through 1.3e.

1.4Affidavit of Addressee

Any person proposing to mail a handgun under 1.3 must file with the postmaster, at the time of mailing, an affidavit signed by the addressee setting forth that the addressee is qualified to receive the firearm under a particular category of 1.3a through 1.3g, and that the firearm is intended for the addressee’s official use. The affidavit must also bear a certificate stating that the firearm is for the official duty use of the addressee, signed by one of the following, as appropriate:

a. For officers of Armed Forces, by the commanding officer.

b. For officers and employees of enforcement agencies, by the head of the agency employing the addressee to perform the official duty with which the firearm is to be used.

c. For watchmen, by the chief clerk of the department, bureau, or independent branch of the government of the United States, the state, the territory, or the district by which the watchman is employed.

d. For the purchasing agent or other designated member of enforcement agencies, by the head of such agency, that the firearm is to be used by an officer or employee included in 1.3c through 1.3e.

1.5Manufacturers and Dealers

Handguns may also be mailed between licensed manufacturers of firearms and licensed dealers of firearms in customary trade shipments, or for repairing or replacing parts.

1.6Certificate of Manufacturers and Dealers

A licensed manufacturer or dealer need not file the affidavit under 1.4, but must file with the postmaster a statement on Form 1508 signed by the mailer that he or she is a licensed manufacturer or dealer of firearms, that the parcels containing handguns (or major component parts thereof) are customary trade shipments or contain such articles for repairing or replacing parts, and that to the best of his or her knowledge or belief the addressees are licensed manufacturers or dealers of firearms.

1.7FBI Crime Detection Bureaus

Handguns may be mailed without regard to 1.3 through 1.6 if:

a. Addressed to the Federal Bureau of Investigation (FBI), or its director, or to the scientific laboratory or crime detection bureau of any agency whose members are federal law enforcement officers or officers of a state, territory, or district authorized to serve warrants of arrest or commitment; or

b. Offered by an authorized agent of the federal government as an official shipment to any qualified addressee in categories 1.3a through 1.3g, or to a licensed manufacturer or dealer of firearms or to a federal agency.

2.0 Antique Firearms

Antique firearms sent as curios or museum pieces may be accepted for mailing without regard to 1.3 through 1.6.

3.0 Rifles and Shotguns

Although unloaded rifles and shotguns not precluded by 1.1e and 1.2 are mailable, mailers must comply with the Gun Control Act of 1968, Public Law 90-618, 18 USC 921, et seq., and the rules and regulations promulgated thereunder, 27 CFR 178, as well as state and local laws. The mailer may be required by the USPS to establish, by opening the parcel or by written certification, that the gun is unloaded and not precluded by 1.1e.

4.0 Legal Opinions on Mailing Firearms

Postmasters are not authorized to give opinions on the legality of any shipment of rifles or shotguns. Contact the nearest office of the Bureau of Alcohol, Tobacco and Firearms for further advice.

5.0 Knives and Sharp Instruments


Knives (including sharp-pointed instruments such as stilettos that lack cutting edges) with a blade that opens automatically by hand pressure applied to a button or other device in the handle, or by operations of inertia, gravity, or both, or with a detachable blade propelled by a spring-operated mechanism, are mailable only when sent to:

a. The respective government’s or organization’s designated supply or procurement officers and employees ordering, procuring, or buying such knives for use with the activities of the federal government; the National Guard, the Air National Guard, or the militia of a state, territory, or the District of Columbia; or the municipal government of the District of Columbia or of the government of any state or territory, or of any county, city, or other political subdivision of a state or territory.

b. Manufacturers of such knives, or bona fide dealers of such knives, in connection with a shipment made under an order from any person designated in 5.1a.

5.2Addressee Identification

Before delivering a shipment (or parcel) that contains an article or articles described in 5.1, a USPS employee may require that the recipient identify himself or herself as in one of the categories in 5.1a.


Sharp-pointed or sharp-edged instruments such as knives, tools, ice picks, and razor blades, that are otherwise mailable, must be wrapped to protect their points and edges from cutting through the outer carton in which they are mailed.

6.0 Prohibited Parcel Marking

For any parcel containing a firearm or a ballistic or switchblade knife, any marking that indicates the contents is not permitted on the outside wrapper or container.

7.0 Intoxicating Liquor

A potable beverage is nonmailable if it is of 0.5% or more alcoholic content by weight, which is taxable under Chapter 51, Internal Revenue Service Code. The product may be mailed if it conforms to applicable requirements of the Internal Revenue Service and Food and Drug Administration and is not an alcoholic beverage, poisonous, or flammable.

8.0 Matter Emitting Obnoxious Odor

Any matter that is a source of an obnoxious odor is nonmailable.

9.0 Liquids and Powders

9.1Liquids and Semisolids

Liquids and semisolids that may liquefy under normal conditions and are otherwise mailable must be adequately prepared for mailing under C010.


Powders that, if allowed to escape from their containers, could cause damage, discomfort, destruction, or soiling, must either be packed in siftproof containers or in other containers sealed in durable siftproof outer containers.

10.0 Motor Vehicle Master Keys and Locksmithing Devices

10.1Motor Vehicle Master KeyDefinition

A motor vehicle master key is any key (other than the key furnished by the manufacturer with the motor vehicle, or the key furnished with a replacement lock, or an exact duplicate of such keys) designed to operate two or more motor vehicle ignition, door, or trunk locks of different combinations, including any pattern, impression, or mold from which such a master key can be made (18 USC 1716A; 39 USC 3002).


Any motor vehicle master key, as defined in 10.1, and any advertisement for the sale of such item, are nonmailable, unless sent to any of the following:

a. Lock manufacturer.

b. Professional locksmith.

c. Motor vehicle manufacturer or dealer.

d. Federal, state, or local government agency.


Any marking identifying the contents is not permitted on the outside wrapper or container of any parcel containing motor vehicle master keys.

10.4Locksmithing DeviceDefinition

A locksmithing device is:

a. A device or tool (other than a key) designed to manipulate the tumblers in a lock into the unlocked position through the keyway of such lock.

b. A device or tool (other than a key or a device or tool under 10.4a) designed for bypassing a lock or similar security device, or for opening it by a method normally not used by consumers to open such locks or security devices.

c. A device or tool designed for making an impression of a key or similar security device to duplicate such key or device.


Any locksmithing device, as defined in 10.4, is nonmailable, unless sent to any of the following:

a. Lock manufacturer or distributor.

b. Bona fide locksmith.

c. Bona fide repossessor.

d. Motor vehicle manufacturer or dealer.

e. Bona fide automotive repair shops or businesses.

11.0 Controlled Substances


A controlled substance means any anabolic steroid, narcotic, hallucinogenic, stimulant, or depressant drug in Schedules I through V of the Controlled Substances Act, 21 USC 801, et seq., and 21 CFR 1300, et seq. If distribution of a controlled substance is unlawful under 21 USC 801, et seq., and any implementing regulation in 21 CFR 1300, et seq., then distribution of such matter by mail also is unlawful under 18 USC 1716.

11.2Mailing Standards

If distribution of a controlled substance is lawful under 21 USC 801, et seq., and any implementing regulation in 21 CFR 1300, et seq., the USPS considers such distribution by mail to constitute the mailing of matter not outwardly or of its own force dangerous or injurious to a person's life or health and accordingly mailable, subject to these standards:

a. The inner container of any package containing controlled substances is marked and sealed under the applicable provisions of the Controlled Substances Act (21 USC 801, et seq., and any implementing regulation in 21 CFR 1300, et seq.) and placed in a plain outer mailing container or securely overwrapped in plain paper.

b. If the mailing includes prescription drugs containing controlled substances, the inner container is also labeled to show the prescription number and the name and address of the pharmacy, practitioner, or other person dispensing the prescription.

c. The outer mailing wrapper or container is free of markings that indicate the nature of the content.

12.0 Drug Paraphernalia

12.1Definition and Examples

It is unlawful to use domestic or international mail to transport drug paraphernalia. The term drug paraphernalia refers to any equipment, product, or material of any kind primarily intended or designed for use in manufacturing, compounding, converting, concealing, producing, processing, preparing, injecting, ingesting, inhaling, or otherwise introducing into the human body a controlled substance, possession of which is unlawful under the Controlled Substances Act. Examples of drug paraphernalia are items primarily intended or designed for use in ingesting, inhaling, or otherwise introducing marijuana, cocaine, hashish, hashish oil, PCP, or amphetamines into the human body, such as metal, wooden, acrylic, glass, stone, plastic, or ceramic pipes with or without screens, permanent screens, hashish heads, or punctured metal bowls; water pipes, chamber pipes, carburetor pipes, electric pipes, ice pipes or chillers, and air-driven pipes; carburetion tubes and devices; smoking and carburetion masks; roach clips (i.e., objects used to hold burning material that is too small or short to be held in the hand); miniature spoons with level capacities of 1/10 cubic centimeter or less; chillums; bongs; wired cigarette papers; and cocaine freebase kits.


In determining whether an item constitutes drug paraphernalia, in addition to all other logically relevant factors, these factors may be considered:

a. Oral or written instructions or other descriptive materials provided with the item that explain or depict its use.

b. National and local advertising on its use.

c. The manner in which the item is displayed for sale.

d. Whether the owner, or anyone in control of the item, is a legitimate supplier of like or related items to the community, such as a licensed distributor or dealer of tobacco products.

e. Direct or circumstantial evidence of the ratio of sales of the items to the total sales of the business enterprise.

f. The existence and scope of legitimate uses of the item in the community.

g. Expert testimony on its use.


The standards in 12.1 and 12.2 apply neither to any person authorized by local, state, or federal law to manufacture, possess, or distribute items described in 12.1 or 12.2; nor to any item that, in the normal lawful course of business, is sold through the mail and traditionally intended for use with tobacco products, including any pipe, paper, or accessory.

13.0 Household Substance

A household substance (39 USC 3001(f)), i.e., any matter unsolicited by the addressee, that contains a substance as defined by section 2 of the Poison Prevention Packaging Act of 1970 (15 USC 1471(2)), is permitted in the mail only if it complies with the requirements for special child-resistant packaging established for that substance by the Consumer Product Safety Commission (16 CFR 1700).

14.0 Pesticide

A pesticide (18 USC 1716), i.e., any matter that contains a pesticide as defined by section 2 of the Federal Insecticide, Fungicide, and Rodenticide Act (7 USC 136(u)), is permitted in the mail only if it complies with child-resistant packaging standards established by the Environmental Protection Agency applicable to that particular matter (40 CFR 157) and meets the applicable standards in C023.

15.0 Fragrance Advertising Sample

A fragrance advertising sample (39 USC 3001(g)), i.e., any matter normally acceptable in the mail but containing a fragrance advertising sample, is permitted in the mail only if it is sealed, wrapped, treated, or otherwise prepared in a manner reasonably designed to prevent individuals from being unknowingly or involuntarily exposed to the sample. A sample meets this requirement if it uses paper stocks with a maximum porosity of 20 Sheffield units or 172 Gurley-Hill units treated exclusively with microencapsulated oils, and if the sample is produced so that it cannot be activated except by opening a glued flap or binder or by removing an overlying ply of paper.

16.0 Compliance Certificate

A mailer who presents matter that is generally permitted in the mail under 13.0, 14.0, and 15.0 but for compliance with the specified packaging and preparation requirements may submit an accompanying written statement certifying that the matter is packaged or prepared under the applicable federal laws and postal standards. The certifying statement may be made on the mailer's letterhead, on a postage statement, or as a notice on the exterior of each item presented for mailing.

17.0 Battery-Powered Devices

Any device powered by dry-cell batteries must have the batteries removed or deactivated to prevent activating the device in the mail. A battery with liquid electrolyte is not permitted in the mail unless it is a nonspillable type battery that meets the standards in C023.


Pens, pencils, key rings, bottle caps, and other similar odd-shaped items are not permitted in letter-size or flat-size paper envelopes unless they are wrapped within the other contents of the envelope to streamline the shape of the mailpiece and prevent damage during postal processing. If an odd-shaped item is not properly wrapped, it could burst through the envelope and cause injury to employees and damage to USPS processing equipment. Odd-shaped items that are properly wrapped within paper envelopes and sent at the First-Class Mail or Standard Mail nonautomation rates may be subject to the nonmachinable surcharge under E130 or E620, as applicable. Certain types of odd-shaped items, when properly wrapped, are permitted as automation rate letter-size mail subject to the standards in C810. Flat-size automation rate mail is subject to the uniform thickness requirement in C820.

19.0 Abortive and Contraceptive Devices

19.1Abortion Devices

Any article or thing designed, adapted, or intended for producing abortion is not permitted in the mail (18 USC 1461).


Unsolicited samples of an article or thing designed, adapted, or intended for preventing conception is permitted in the mail only when sent to a manufacturer or a dealer of such an article or things, to a licensed physician or surgeon, or to a nurse, pharmacist, druggist, hospital, or clinic (39 USC 3001; 18 USC 1461).

20.0 Building Construction Material

Building construction material is not permitted in the mail if the acceptance and processing is likely to harm or injure USPS employees, mail, or equipment. Factors considered include but are not limited to whether the material may pose potential storage problems at the postal facilities that may process the material; whether the volume of material may impede the flow of mail in USPS transportation or mail distribution systems; whether the volume of material may lead to security problems; and whether processing the material may create safety hazards for USPS employees.

DMM Issue 58 (8-10-03)