Auditor Change

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 ​ FORM 8-K ​ Current Report Pursuant to Section 13 or 15 (d) of the Securities Exchange Act of 1934 ​ Date of Report (Date of earliest event reported): March 27, 2025 CSP Inc. (Exact name of the registrant as specified in its charter) ​ Massachusetts (State or other jurisdiction of incorporation) ​ ​ ​ 000-10843 04-2441294 (Commission File Number) (IRS Employer Identification No.) ​ ​ ​ 175 Cabot Street - Suite 210 , Lowell , MA 01854 (Address of principal executive offices) (Zip Code) ​ ( 978 ) 954-5038 (Registrant’s telephone number, including area code) ​ Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ​ ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) ​ Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ 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. ☐ ​ Securities registered pursuant to Section 12(b) of the Act: Title of Each Class Trading Symbol(s) Name of each exchange on which registered Common Stock, par value $0.01 per share CSPI Nasdaq Global Market ​ ​ Item 4.01   Changes in Registrant’s Certifying Accountant. ​ As previously announced on February 14, 2025, in a filed Form 8-K with the Securities and Exchange Commission, the Audit Committee selected CBIZ CPAs P.C. (“ CBIZ ”) as the Company’s independent registered public accounting firm for the Company’s fiscal year ending September 30, 2025, subject to completion of CBIZ client acceptance. As of March 27, 2025, CBIZ’s client acceptance procedures have been completed. ​ SIGNATURE ​ ​ Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. ​ Date: March 31, 2025 CSP INC. ​ ​ By: /s/Gary W. Levine Name: Gary W. Levine Title: Chief Financial Officer ​ ​ ​ ​