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Vehicle and Engine Certification

Certification for Heavy-Duty (HD) Commercial Trucks and Buses and Onroad HD Engines

Follow these steps for certification.

STEP 1: Confirm that you have access to Verify.

You must register with EPA to gain access to the Verify system for the specific manufacturer code  for which you are seeking certification.
You must also set up an account with EPA to establish the necessary Verify roles.

STEP 2: Update manufacturer information in Verify.

To update information, users must have the "Maintain Manufacturer Information" role in the Verify system. Otherwise, users will only be able to view  the information.

Information to Update

Updates include (but are not limited to):
  • Industry sector(s);
  • Addresses;
  • Contacts and Industry/Compliance Programs;
  • Test labs; and
  • Notification email addresses (used for Verify's broadcast notifications).

STEP 3: Review all applicable regulations.

Regulations provide requirements for certification and compliance.


Review the following:

You will need Adobe Reader to view some of the files on this page. See EPA’s About PDF page to learn more.

STEP 4: Pay appropriate certification fees, as applicable.

A fee payment may be required for each certificate issued by EPA.

For more details, go to: Fees Information

STEP 5: Prepare certification application materials.

For each model year for an Engine Family, you must provide the applicable certification dataset and supporting materials.

Support Documentation for Submissions

Materials Specific to Heavy-Duty (HD) Commercial Trucks & Buses and HD Engines

Materials for All Verify Users

STEP 6: Submit the completed certification application materials
in Verify.

Login to the Verify System through the CDX portal: Central Data Exchange (CDX)

Click the applicable industry role on the MyCDX homepage.

Submit the completed certification dataset and upload any required supporting materials.

STEP 7: Confirm that your submission(s) from Step 6 were accepted by Verify.

Within a few minutes of all submissions, the submitter will receive a notification in their CDX inbox indicating whether the submission was accepted or rejected.

To access your CDX inbox, click the "Inbox" link on the left navigation bar of the MyCDX homepage.

STEP 8: Submit a request for certificate (RFC).

A CROMERR signer must submit an RFC for each Engine Family.

To do so, click the "CROMERR Signer" role on your MyCDX homepage.

Additional resource:

STEP 9: Receive Certificate of Conformity.

The CROMERR signer will receive the certificate in his or her CDX inbox.

To access your CDX inbox, click the "Inbox" link on the left navigation bar.