49 CFR § 385.405T - How does a motor carrier apply for a safety permit?
(a) Application form(s).
(1) To apply for a new safety permit or renewal of the safety permit, a motor carrier must complete and submit Form MCS-150B, Combined Motor Carrier Identification Report and HM Permit Application.
(2) The Form MCS-150B will also satisfy the requirements for obtaining and renewing a USDOT Number; there is no need to complete Form MCS-150, Motor Carrier Identification Report.
(b) Where to get forms and instructions. The forms listed in paragraph (a) of this section, and instructions for completing the forms, may be obtained on the internet at http://www.fmcsa.dot.gov, or by contacting FMCSA at Federal Motor Carrier Safety Administration, Office of Registration and Safety Information (MC-RS), 1200 New Jersey Ave. SE, Washington, DC 20590-0001 or by telephone at 1-800-832-5660.
(c) Registration with the Pipeline and Hazardous Materials Safety Administration (PHMSA). The motor carrier must be registered with PHMSA in accordance with part 107, subpart G, of this title.
(d) Updating information on Form MCS-150B. A motor carrier holding a safety permit must report to FMCSA any change in the information on its Form MCS-150B within 30 days of the change. The motor carrier must use Form MCS-150B to report the new information (contact information in paragraph (b) of this section).