(This page printed from UtahRails.net, Copyright 2000-2019 Don Strack)

AAR Reporting Marks

Index For This Page

This page was last updated on July 5, 2015.

(Return to Utah Railroads Index Page)


An AAR (Association of American Railroads) reporting mark is two to four letters, and a number from 1 to 999999 that uniquely identifies the owner of a piece of railroad equipment. This includes freight cars and passenger cars, as well as non-revenue equipment used by railroads. The reporting mark is generally derived from the assigned company's initials. All rail cars in interchange service from one railroad to another must be labeled with a reporting mark. A single railroad may have numerous reporting marks due to a history of mergers and acquisitions.

Marks other than X, U or Z are assigned to common carrier railroads for use on railroad equipment in interchange service.

Marks that end in X are assigned to non-common carrier rail car owners. These include private car owners, leasing companies, and railroad museums.

Marks that end in U are assigned to owners of intermodal shipping containers.

Marks that end in Z are assigned to owners of intermodal trailers and trailer chassis.

Historical Background

(research continues)

Current Usage

The following comes from portions of the online "Guide For Railroads" from AAR.

I. Introduction

A. About The Guide

This document is designed to introduce new and existing railroads to valuable information for operating as a part of the North American railroad system. Each section in this document describes the uses and requirements of an application or process, outlines Railinc’s role and, where applicable, the various rules and procedures prescribed by the Association of American Railroads (AAR), Surface Transportation Board (STB), and National Motor Freight Traffic Association (NMFTA).

The management of many of these applications/processes is handled by different disciplines in different locations. The AAR, located in Washington, D.C., is responsible for the promulgation and interpretation of Car Service/Car Hire Rules and Interchange Rules. The Transportation Technology Center, Inc. (TTCI), located in Pueblo, Colorado, is responsible for the development and testing of new and existing freight and passenger equipment technology. Railinc, located in Cary, North Carolina, is the leading provider of information technology development and related services to the North American Railroad Industry. In addition, AAR has contracted with Railinc and TTCI to provide administrative support as wholly owned subsidiary companies of the AAR.

II. Assignment Of Reporting Marks And Railway Accounting Rule 260 Code

One of the important functions managed by AAR is the assignment of the Standard Carrier Alpha Code (SCAC) which consists of two to four alpha characters, and the Railway Accounting Rule 260 Code which consists of 3 numeric digits. A SCAC throughout this document will be referred to as a Reporting Mark or Car Initials. The reporting mark is used in conjunction with the Railway Accounting Rule 260 Code as a company’s identification for various tariff and accounting applications. The reporting mark is stenciled on its equipment. The requirements for the assignment of all railroad reporting marks are outlined in Circular Letter OT-5.

A. Reporting Marks For Rail Equipment

A reporting mark will be assigned to a railroad upon receipt of authority issued by the Surface Transportation Board (STB), or the Certificate of Fitness issued by the Canadian Authority, or the Concession issued by the Mexican Government and a signed interchange agreement.

Only one reporting mark will be assigned to a railroad. This is a requirement of the NMFTA that is empowered by the STB to administer the assignment of reporting marks for all modes of transportation. Carriers that were merged and/or assigned equipment marks prior to the STB’s transfer of responsibility to NMFTA may retain those reporting marks as equipment identifiers only.

When applying for a reporting mark, a copy of the AAR Interchange Agreement, Section 10706 Agreement and Car Service/Car Hire Agreement will be furnished. The reporting mark will not be assigned until the executed AAR Interchange Agreement is received. In addition, the applicant is to provide a brief outline of its operations and/or adoption notice identifying stations, junction points and railroad(s) that will be its interchange partner(s).

The AAR "Request For Railroad Reporting Marks" application shows that as of July 2015, there is a $525.00 admistrative fee to have a reporting mark issued.

Contact RaiLinc customer support at 1-800-544-7245.

RaiLinc web site

AAR Guide For Railroads; May 30, 2013 (PDF; 57 pages)

AAR Circular Letter OT-5; January 1, 2009 (PDF; 3 pages)

FRA Search Railroad Name or Code

FRA Guide for Preparing Accident/Incident Reports (PDF; 315 pages; see Appendix A for list of railroads)

More Information

Ian Cranstone's Listing of AAR Reporting Marks

Piedmont & Western Railroad Club Listing of AAR Reporting Marks

Railfan.net Listing of AAR Reporting Marks