Mail Services: January 2024 Changes to Mailer IDs and Mail Stop Numbering

As of January 2024, Billing IDs have transitioned to Mailer IDs, and there is a new numbering system for departmental Mail Stops.

New Method of Assigning Departmental Mailer IDs

The Billing IDs departments include as part of their return address to charge back postage costs have been discontinued as part of the transition to the new UC Chart of Accounts, implemented at UC Davis in July 2023.  As a result, Billing IDs have been replaced with Mailer IDs. Similar to how Billing IDs functioned, the Mailer IDs are a four-digit alias to the department’s new UC Chart of Accounts.  Departments request Mailer IDs directly from Mail Services via AggieLogistics.

In AggieLogistics, departments can search for their departmental Mailer IDs.  

Creating a New Mailer ID (Effective January 2024)

  1. Department fills out a Mail Services form in AggieLogistics to request a Mailer ID for each new Chart of Account string for which they would like to process outgoing US Mail against.  Departmental staff enter their contact information, department name, and Chart of Account string.
  2. Mail Services assigns a Mailer ID for customers to include on their outgoing mail and packages that require postage to be added by Mail Services before dispatching through the USPS.

Introduction of the Mail Stop Number (MSN)

Mail Services has adopted a numerical numbering system for delivery locations at Campus and UCDH, that will be identified in the format, MS ("Mail Services") followed by a 5-digit number, e.g., MS00001.

The Mail Stop Number (MSN) expedites the delivery of mail, as well as makes it easier for automated sorting equipment to read mail pieces and route them correctly to their final delivery destination.

For departments with existing Mail Stops, Mail Services has assigned MSNs.  Use AggieLogistics  to search for these departmental MSNs.  

Creating a New MSN (Effective January 2024)

To request a new MSN, departments complete a Mail Services form in AggieLogistics.  


Contact Mail Services at