You can report suspected tax fraud and abusive tax preparers to the IRS on Form 3949-A, Information Referral or by sending a letter to Internal Revenue Service, Fresno, CA 93888. Download Form 3949-A from IRS.gov or order by mail at 800-829-3676. | You can report suspected tax fraud and abusive tax preparers to the IRS on Form 3949-A, Information Referral or by sending a letter to Internal Revenue Service, Fresno, CA 93888. Download Form 3949-A from IRS.gov or order by mail at 800-829-3676. |