Mailing and Shipping Solutions Center (MSSC) Topics

List of topics the MSSC can assist with. To reach the MSSC, email us at MSSC@usps.gov or call 1-877-672-0007 from 7:00AM – 7:00PM CT.

Quick Reference Guide: Bundle Preparation and Handling Recommendations

A guide to ensuring your bundles stay secure during transit.

2026 Integrated Technology Enrollment Guide

Service Standards File Layouts/Release Notes

The Postal Service is making service standard changes to support Delivering for America network changes. We continue to provide service standard data files for customer use to determine the number of days in transit. This tech sheet will provide file layouts to help customers understand ongoing and upcoming changes associated with the proposed changes. Along with file layout changes, we are now incorporating Presort First-Class Service Standards.

Package Tracking Options and Modernization

Explore package tracking options with our Product Tracking and Reporting (PTR) application and learn about the planned changes in our recent platform modernization efforts.