22 Marking Requirements

221 General

To avoid rejection of the mailpiece by Postal Service acceptance personnel or air carriers, mailers must ensure that their packages meet all applicable labeling, marking, and ancillary endorsement requirements.

221.1 Address Side of Mailpiece

Hazardous materials and restricted or perishable matter, unless specifically excepted in 222, must be clearly marked, labeled and identified on the address side of the mailpiece (see 325.1 and DMM section 102.1.1 and 202.1.1). Only in limited situations where sufficient space does not exist, DOT markings may be placed on a side adjacent to the address. Markings and labels must not be placed on the bottom of a package or envelope. Other markings required by the Postal Service or other federal regulatory agencies also must appear on the address side of any mailpiece containing hazardous material, restricted matter, or perishable matter as specified in 325.1. Required markings must be applied with an insoluble material or other material that cannot be rubbed off or smeared.

221.11 Return Address

Except for diagnostic specimen mailpieces using a Business Reply Mail format, and nonregulated materials, a return address that includes the sender’s name and address must appear on all packaging containing hazardous, restricted, or perishable mail.

221.12 Content Markings

When required, the contents also must be clearly identified on the address side. The contents must be disclosed to be mailable. A mailability determination may be required based on the mailer’s disclosure concerning the contents at the time of mailing.

221.2 Ancillary Endorsements

A mailer endorsement may be used to request forwarding, return, or address correction service for items that are undeliverable as addressed (see DMM 507).

Standard Mail and Parcel Select Lightweight pieces containing hazardous materials must bear the endorsement “Address Service Requested,” “Forwarding Service Requested,” or “Return Service Requested.”

First-Class Mail, First-Class Package Service, Priority Mail, Standard Mail, USPS Retail Ground, Package Services, or Parcel Select (including Parcel Select Lightweight) pieces containing hazardous materials cannot use “Change Service Requested.”