Fact Sheets
03/03/2026
Ancillary Service Endorsement Fact Sheet

Ancillary service endorsements are used by mailers to request an addressee’s new address or the reason mail cannot be delivered as addressed and to provide the US Postal Service with instructions on how to handle Undeliverable As Addressed (UAA) mailpieces.

Fact Sheets
03/03/2026
Ancillary Service Endorsement Fact Sheet

Ancillary service endorsements are used by mailers to request an addressee’s new address or the reason mail cannot be delivered as addressed and to provide the US Postal Service with instructions on how to handle Undeliverable As Addressed (UAA) mailpieces.

Applications/ Forms
05/23/2025
ACS™ Enrollment Form

This document is the enrollment form for ACS™.

User Guides
01/18/2024
Guide to Move Update

The Move Update standard is a means of reducing the number of mailpieces in a mailing that require forwarding or return by the periodic matching of a mailer’s address records with change-of-address orders received and maintained by the Postal Service.

FAQs
07/06/2022
Ancillary Services for Parcel Select and Parcel Select Lightweight FAQs

Frequently Asked Questions for Ancillary Services for Parcel Select and Parcel Select Lightweight

FAQs
07/06/2022
Ancillary Services for Parcel Select and Parcel Select Lightweight FAQs

Frequently Asked Questions for Ancillary Services for Parcel Select and Parcel Select Lightweight