The Mailer Identifier (MID) is a field within the Intelligent Mail barcode that is used to identify mailers. MIDs are assigned by the USPS^® to a Mail Owner, Mailing Agent or other service providers who request them.

The USPS^® Customer Registration ID (CRID) is a unique number that identifies a specific business location involved in a mailing. In order to submit electronic documentation (and receive Full-Service benefits), customers must have a customer registration ID assigned to their business location. 

The Mailer Scorecard provides a dashboard view of the results of the letter and flat mailing activity with the Postal Service over a calendar month. This view is available to both the mailer who submitted the electronic documentation for the mailing (eDoc submitter) and the mail owner/mail preparer. 

The Electronic Verification System (eVS^®) enables parcel mailers to submit documentation and pay postage by transmitting electronic manifest files to the eVS database.