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OneCode ACS®

OneCode ACS allows customers mailing First-Class Mail®, Standard Mail®, and Periodical flats or letters to receive electronic or automated address corrections using the Intelligent Mail® barcode.

Who is OneCode ACS for?

First Class Mail
Standard Mail


What is OneCode ACS?

OneCode ACS allows customers mailing First-Class Mail, Standard Mail, and Periodical flats or letters to receive electronic or automated address corrections using the Intelligent Mail barcode. OneCode ACS is the basis for the creation of Full Service ACS notices that are provided to qualified Full Service mailers.

How does OneCode ACS work?

The USPS® can forward mail or notify mailers of a Change of Address (COA) only if the customer submits a change of address request with the Postal Service™.

There are cases where the Postal Service knows the customer has moved but did not notify the USPS, so the delivery employee submits a COA as “Moved, Left No Address” (MLNA - DNF Code: K) or “Box Closed No Order” (BCNO - DNF Code G). Hereafter, this process will be referred to as USPS-Filed Actions. These records are included in the COA database and therefore are fulfilled as COA Notices that do not contain a new address. These notices contain the original (old) address information from the COA and a DNF (Do Not Forward) code.

When a mailpiece is intercepted by the Postal Automated Redirection System (PARS) or identified by delivery personnel as Undeliverable as Addressed (UAA) due to customer relocation, the following occurs:

  • The mailpiece (depending on its class, size, and endorsement) is either processed by the PARS equipment or sent to the Computerized Forwarding System (CFS) responsible for processing mail destined to that delivery address.
  • An attempt is made to match the name and address to a COA.
  • If there is a match and the mailpiece bears a readable, valid Intelligent Mail barcode with the required fields properly completed, an electronic or automated OneCode ACS notice is generated.
  • The mail class (First-Class Mail, Periodical, Standard Mail, or Bound Printed Matter), the mailer’s requested ancillary service, and the age or existence of a COA determines whether the mailpiece is forwarded, discarded, or returned to sender.
  • OneCode ACS notices are transmitted from the Postal mail processing facilities to the NCSC, where they are categorized by the participating Intelligent Mail barcode Mailer Identifier (Mailer ID) and then distributed to the mailers daily via the Electronic Product Fulfillment (EPF) secure web-based fulfillment resource.

SingleSource ACS


Full-Service ACS notices are created in the same environment as described for OneCode ACS. The NCSC distributes Full Service ACS notices to PostalOne!® based on the Service Type ID in the Intelligent Mail barcode. PostalOne! processes and fulfills the notices to the mailers daily via the Business Customer Gateway.


Full-Service mailers that include both full-service and basic (OneCode®) ACS Service Type IDs in their IMb can receive all of their ACS notices in a daily file provided via download from the Electronic Product Fulfillment secure web service. Information and instructions for this fulfillment option can be found in the SingleSource ACS Technical Guide.

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Related Products

Traditional ACS™

Traditional ACS is one of the four ways to participate in ACS, where mailers notifications of undeliverable mail (UAA) and change-of-address (COA) electronically. The Intelligent Mail® barcode is not required to receive Traditional ACS. 


ACS is a post mailing service that allows mailers to receive change-of-address (COA) and other reasons for non-delivery electronically and reduce the number of manual (hardcopy) address notifications.


The NCOALink Product is a secure dataset of approximately 160 million permanent change-of-address (COA) records consisting of names and addresses of individuals, families and businesses who have filed a change of address with the Postal Service™. Developed with secure data store technology to increase security of postal customer data and protect the privacy of this information, the NCOALink Product enables mailers to process mailing lists and update lists with new addresses prior to mailing. The NCOALink data is provided on a regular basis to companies that have been licensed by the Postal Service.



For more information about the OneCode ACS, access or call 877-640-0724 Call: 877-640-0724.