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UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 ( Mark One ) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended September 30 , 2021 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from Delaware ( State or other jurisdiction of incorporation or organization ) Form 10 - K 8550 Mosley Road Houston Texas ( Address of principal executive offices ) to Powell Industries , Inc. ( Exact name of registrant as specified in its charter ) Commission File Number 001-12488 Title of each class Common Stock , par value $ 0.01 per share Registrant's telephone number , including area code : ( 713 ) 944-6900 Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol POWL 88-0106100 ( I.R.S. Employer Identification No. ) Securities registered pursuant to Section 12 ( g ) of Act : None 77075-1180 ( Zip Code ) Name of each exchange on which registered NASDAQ Global Market Indicate by check mark whether the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes > No Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Act . Yes > No Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes No Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S - T ( §232.405 of this chapter ) during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes No Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company or an emerging growth company . See the definitions of " large accelerated filer , " " accelerated filer , " " smaller reporting company " and emerging growth company in Rule 12b - 2 of the Exchange Act . Large accelerated filer ■ Accelerated filer X Non - accelerated filer ■ Smaller reporting company n If an emerging growth company , indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13 ( a ) of the Exchange Act . Emerging growth company Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Act ) . Yes No