Full‐Service Requirement: Mailing Agent (By) and Mail Owner (For) information must be identified in the electronic documentation for all Full-Service mailings. Mail Owner and Mailing Agent data may be provided through a Mailer ID (MID), Customer Registration ID (CRID), Permit Number, or Publication Number. The USPS recommends providing only one of the fields for any Mail Owner in the mailing. Read more.
Via USPS RIBBS