Data Files
07/20/2026
Data Files
07/20/2026
Data Files
07/20/2026
Move to Competitive Street Addressing (MTC SA) List

This .txt file contains the MTC SA List.

User Guides
07/20/2026
Domestic Merchant Returns API: User Guide

This user guide provides examples of XML transactions to the USPS Merchant Returns web service and guidance for installation.

Presentations
07/17/2026
PS Form 3500 Application For Periodicals Mailing Privileges

PS Form 3500 presentation for completing and submitting the application to the PCSC.

Release Notes
07/17/2026
Error Codes
07/17/2026
Applications/ Forms
07/17/2026
NCOALink® Software Developer License Agreement v29 (7/15/2026)

This agreement licenses the development of software interfaces for the NCOALink® product.