Customer Service Form For all inquiries to SEMA’s Customer Service Team, please use the form below. The appropriate staff member will respond to your request within 24 hours during business days. You can also contact SEMA via phone at 909-610-2030 and speak to a Customer Service Team member immediately. If you would like to contact SEMA via mail, please use the address listed below: SEMA Headquarters, 1575 S. Valley Vista Drive, Diamond Bar, CA 91765 First Name * Last Name * Your E-Mail * Subject * Categories * - Select -General InquiryClassifiedsCouncils and CommitteesEventsEducationGovernment AffairsJoin SEMAPressPublicationsResearchSEMA Education Institute (SEI)SEMA ShowStudents Message * CAPTCHAThis question is for testing whether or not you are a human visitor and to prevent automated spam submissions.