What are the USPS tracking codes?
Express1 & Endicia Tracking Codes
USPS Web API Tracking Codes
This Appendix lists all the possible scan event codes (both current and planned) for domestic Express Mail or Return to Sender mail. The codes appear in positions 144–145 of the EMM extract file and on the Internet lookup site.
- Indicates clock-stopping event. **Scan Events 53, 54, 55, 56 will be provided with Express Mail and when a non Express Mail package is delivered at the same time as an Express Mail package.
Return to Sender Codes