Submit a M # Symbol Approval requests using the PHMSA Portal

Applicants also have the option of submitting request via email to approvals@dot.gov, or mailed to [Department of Transportation, East Building, PHH-33, 1200 New Jersey Avenue SE, Washington, DC 20590]

NOTE: Please attach an individual request, when applying online

The M#/Symbol registration request should contain the following:

• Request Letter as described in 49 CFR Section 107.705 must be sent to the Approvals Office. 
• The Request Letter must contain detail information for the purpose of the M#/Symbol and the item that is being mark with the M#. 
• Provide the name, facility and mailing address, email (optional), and the telephone number of the person on whose behalf the registration or application is made and, if different from the person filing. 
• If the company seeking registration is an international location, they must provide an U.S. Agent name, company, and contact information attached to their request. 

49 CFR References sites for M#/Symbol 

• 107.705
• 178.503