New Carta Porte EDI Requirements

Announcement Number: CN2023-23
Categories: General Announcements
Posted Date: April 12, 2023

To Our Customers,

The Mexican railroads have informed the Association of American Railroads (AAR) that they will begin to require shippers to provide two additional Carta Porte data elements to be compliant with the Mexican Government requirements.

The two new fields for Carta Porte Compliance:

  1. MHP – Mexico Hazardous Packaging Code (Tipo Embalaje) Qualifier
    Required on all hazardous loaded and residue last-contained shipments with an origin or destination within Mexico.
  2. MPC – Mexico Unit Packaging Code (Clave Unidad) Qualifier
    Required on all loaded and revenue empty shipments with an origin or destination within Mexico. Also required on all residue last-contained hazardous with an origin or destination within Mexico.


In order to be compliant, Union Pacific has begun to develop these new fields for our EDI (Electronic Data Interchange) and Waybill Management interfaces. Our target date for completion is June 15, 2023, when we will be able to accept these new values.

Union Pacific will continue to conduct waybill compliance checks before the Mexican Tax Authority begins implementing fines and rejections at the border for non-compliant shipments on August 1, 2023. To avoid penalties from the Mexican government and document delay charges, it is imperative that customers act now to ensure billing information into and out of Mexico is compliant with Carta Porte requirements.

Online Reference Tools
Customers can consult the following updated resources for additional information:

If you have additional questions, please email the Carta Porte team for assistance.