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How do I detach my MC and DOT numbers?

Published 04/20/2015 12:57 PM   |    Updated 08/27/2015 06:56 AM

Situations where a carrier might want to detach their DOT number from an MC number include going from interstate to intrastate carrier or from for-hire to private carrier status. A request to detach can only be fulfilled if the MC number is not currently pending in L&I. If a carrier has an MC number listed as "not-authorized" associated with their DOT number, it can give the appearance that the DOT number is not authorized/carrier is not operating. Such a carrier would benefit from detaching the MC number if they don't intend to reinstate their authority and operate as a for-hire carrier.
To request detachment, please submit:

  • A signed MCS-150 form with "Biennial Update or Changes" checked under "Reason for Filing"
  • Company's current MC and DOT numbers
  • Company name
  • Letter stating request and reason for detachment, signed by an authorized representative of the company (same person who signed the MCS-150)

Submit the request:

  • By email: Upload the signed MCS-150 form and letter and submit them via our web form (best option - you will receive a tracking number)
  • By fax: you can fax the completed and signed form and letter to 202-366-3477 or 606-330-3802
  • By mail: You may mail the completed and signed form and letter to the address indicated on the form
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