Review USPS Publication 52, Hazardous, Restricted, & Perishable MailĬompare All USPS Domestic Mail & Shipping Servicesįast air delivery for your most important mail and packages (with some Flat Rate options). See More Details: Domestic Shipping Prohibitions, Restrictions, & HAZMAT If you have any questions about what you may ship through USPS, review the restricted and prohibited items list. If you don’t follow the rules, you might face fines, or even criminal penalties. You have to follow all laws and USPS regulations.

Some items have special packaging requirements, or can only be sent via ground transport, like perfumes containing alcohol.

Perishable items (like plants or food) are generally OK to send as long as they are properly packaged and won’t spoil or leak.

Lithium batteries (like the ones that come installed inside small electronics, like laptop computers or cell phones) are usually OK to send if the items are new (or a manufacturer-certified repair) if the items are used, they can only be sent via ground transport (can’t go on planes).

Other items are restricted: You have to follow the rules, stick to any limits, and properly package and label your items. Some items are prohibited (completely forbidden): You can’t send them through USPS, so you’ll have to choose another carrier.

Usps flat rate medium box size