Q. DELPHI E-Invoicing System
For all questions regarding the Delphi eInvoicing System, please contact the Customer Service Center Help Desk:
• 1-405-954-3000, Option 4, Option 3
• Toll Free: 1-866-641-3500, Option 4, Option 3
The Help Desk is available from 6:00am ET through 9:00pm ET
Monday – Friday, including holidays.
The web page for this is: https://www.transportation.gov/cfo/delphi-einvoicing-system