The Central Data Exchange (CDX) is an established portal through which electronic data are submitted. All registered parties will have to first register with CDX in order to receive a CDX registration number. More information may be found at Reporting for Fuel Programs.

Question and Answer was originally posted at: Questions and Answers on the Renewable Fuel Standard Program (PDF) (55 pp, 221 K, EPA420-F-07-041a, August 2007, About PDF)