🚫 USPS Prohibited & Non-Mailable Items
What the Postal Service won't send abroad, and why USPS is stricter than the express carriers
USPS uses the term "nonmailable." Anything nonmailable domestically is also nonmailable abroad (IMM 131.1), and many things that can go domestically cannot go internationally. Rules live in the International Mail Manual (IMM), section 130 and Publication 52, plus the destination's Individual Country Listing. The short rule: dangerous goods are barred from outbound international mail in every mail class unless IMM 135 allows them (IMM 136.1). USPS also has a plain-language page on international shipping restrictions.
Prohibited to Every Country
USPS lists these as prohibited in international mail:
Everyday items that surprise people
- Perfume containing alcohol
- Nail polish
- Aerosols
- Alcoholic beverages
- Cigarettes, smokeless tobacco and vapes (IMM 136.4, which overrides the country listings)
- Dry ice
- Mercury in any form, including thermometers and compact fluorescent bulbs
- Most glues, and flammable or combustible paint
- Hemp-based products, including CBD
Hazards and illegal goods
- Explosives and ammunition
- Gasoline, other flammables, oxidizers and corrosives
- Compressed gases and poisons
- Strongly magnetized material
- Air bags
- Marijuana, medical or otherwise
- Counterfeit or pirated articles (IMM 136.3)
- Inert or replica grenades and military ordnance (IMM 136.2)
- Category A infectious substances
Lithium Battery Rules (IMM 135.6)
USPS is much stricter on batteries than the couriers. Only new cells and batteries installed in the equipment they operate can be mailed abroad, within these limits:
| Type | Max per mailpiece | Size limits |
|---|---|---|
| Lithium metal (non-rechargeable: cameras, flashlights) | 4 cells or 2 batteries | Up to 1 g lithium per cell, 2 g per battery |
| Lithium-ion (rechargeable: phones, laptops) | 4 cells or 2 batteries | Up to 20 Wh per cell, 100 Wh per battery, with the Wh rating marked on each battery |
The equipment must be protected against short circuit and accidental activation, and sent in a strong, sealed, cushioned package. The mailpiece must not carry any lithium battery marks or labels, which is the opposite of courier practice.
Prohibited under any circumstances (IMM 135.62):
- New batteries packed with equipment, or sent separately. That includes spares and power banks.
- Used, damaged, defective or recalled batteries, whether installed, packed or loose.
- Used, damaged or defective devices that contain a lithium battery, unless new in original packaging or manufacturer-certified new or refurbished. A used phone sold on eBay is generally not mailable abroad.
Restricted: Mailable With Conditions
Medicines
Prescription medications may be mailed only by DEA-registered distributors, and some over-the-counter drugs face similar rules. Destinations often ban them too.
Cigars
Only to countries that allow them. Check the country listing.
Coins, cash, jewelry
Valuable articles under IMM 134. They go by Priority Mail International, not Priority Mail Express International. Many countries ban them. First-Class Mail International with Registered Mail is an option only where customs treats the item as a document.
Cremated remains
Priority Mail Express International only, in a sealed funeral urn inside a USPS Cremated Remains Kit.
Knives and sharp tools
Some can go to certain countries only (IMM 137). Conditions are in the country listing. Ordinary hand tools are usually fine.
Firearms and arms
Handguns are limited to licensed manufacturers and dealers. Arms exports need State Department licensing (IMM 540). This is not an option for individuals.
Perishables
Sent at your own risk, specially packaged, and arriving before they spoil. Many countries ban them.
Live animals
Pets and warm-blooded animals are generally not mailable. Narrow rules cover poultry, reptiles and bees.
Liquids and powders
Non-hazardous liquids can go if packaged as required, and fragile items and powdered dyes have their own packing rules (IMM 131.5).
The Country Listing Is the Final Word
Articles prohibited by the destination are nonmailable (IMM 131.32), even when USPS would otherwise accept them, and a country may return or seize mail that breaks its rules. To use a listing, open the Individual Country Listing and read "Prohibitions" and "Restrictions" near the top. The entries are specific, and can name used clothing, particular foods, religious material and more. The same listing shows the maximum weight and insurance limit for that country.
The burden is on the mailer. IMM 131.4 puts responsibility for following mailability rules on you, not on the retail clerk who accepts the parcel. Pair the listing with our destination guides.
Also check that the lane is open. USPS suspends acceptance to a changing list of destinations, shown on its international service alerts page.
What Happens if You Mail It Anyway
USPS states that knowingly mailing dangerous materials carries a civil penalty of at least $250 and up to $100,000, plus cleanup costs, damages and possible criminal charges. Indemnity is not paid on parcels containing prohibited articles (IMM 933). See shipping insurance for what is covered.
💡 When USPS won't mail it
- The express carriers can sometimes carry fragrance, alcohol (business only) and standalone batteries that USPS bans, but usually from approved shippers only. See FedEx, UPS and DHL, or the four-carrier comparison.
- Never label a prohibited item as "gift" or "documents" to get it accepted.
- Accurate descriptions matter as much as the contents. See the customs forms guide.