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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.

MIDs are either a 9-digit or a 6-digit numeric code and are assigned based on annual mail volume criteria. One 9-digit MID is assigned to a business location without a volume requirement.

How to obtain a Mailer ID
To request a Mailer ID (MID) go to http://www.usps.com/ and select the Business Customer Gateway located on the bottom right hand corner of the web page

footer. You must either be an existing or a registered user, or can sign-up as a new user for a business account to gain access to the Business Customer Gateway. Once you have access, request the "Mailer ID" tool and proceed with the "Request a MID" button to obtain a MID.

Exception Process
If you need additional MIDs, not obtainable through the Business Customer Gateway-MID Tool, refer to the Mailer ID Exception Process. Mailing Agents who are authorized to obtain MIDs on behalf of Mail Owners, should refer to the Agent Application Process. All forms can be viewed and printed from the Important Links box on this web page. Complete the Mailer ID Application and the Additional Accounts Information sheet if applicable and submit them to the Business Mail Entry Unit (BMEU) or the Mailpiece Design Analyst for processing.

To locate your local Business Mail Entry Unit (BMEU) or Mailpiece Design Analyst (MDA), go to the following URLs:
www.usps.com/nationalpremieraccounts/findlocators.htm (BMEU locator)
https://ribbs.usps.gov/mda/mda.cfm (MDA look-up tool)

Program Registration Mailer ID Assignment
For shippers who enroll in Shipping Service programs using the Business Customer Gateway, one 9-digit (master) Mailer ID is initially assigned. Subsequent 9-digits are assigned based on a Mail Owner single business or a mail service provider's single-client business shipping location.

Contact Information:

Important Updates

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Coming Soon: PostalPro

The RIBBS website has been redesigned and is in the process of transitioning to a new home called PostalPro. www.postalpro
will become the primary source for USPS mailing information.

PostalPro leverages powerful search functionality, intuitive navigation, and a modernized, mobile-friendly design.

Upcoming 2017 Releases

Upcoming 2017 Releases

January 2017 Price Change Fact Sheet

January 2017 Release Overview

January 2017 Release Notes

Market Dominant Pricing Files

Click here for weekly Incorrect Scanner Configuration Report

Click here for 2015 Network Consolidations

Click here for Mail Processing Current and Future Operating Plan

Click here for Network Rationalization Service Standard Analysis

Click here for Plants with Remittance Mail Documents

Click here for Customer Letter regarding 2015 Network Consolidations

Click here for the new Service Type ID information page

Service Hub Facilities

Service Hubs – Mail Prep and Entry

Presort Reference Data Issue Log

FAST Label List Test Data

FAST Enhancements September 25, 2016

IV Migration Overview

Getting Started with Full-Service Intelligent Mail

PostalOne! Contingency Plan

For mailers unable to submit electronic information, click here for the PostalOne! Contingency Plan.


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