SMX（安全事务）PLC美股招股说明书（2025-10-23版）

SMX (SECURITY MATTERS) PUBLIC LIMITED COMPANY Issuance of up to 22,590,361 Ordinary Shares This prospectus supplement (this “Prospectus Supplement”) is being filed to update and supplement our prospectus containedin our Form F-1, dated September 30, 2025 (the “Prospectus”), relating to the resale, from time to time of up to an aggregate of22,590,361 ordinary shares of the Company, $0.00000000000312817946 par value per share (“Ordinary Shares”), by the sellingstockholders named elsewhere in the Prospectus (“Selling Stockholder”). The Ordinary Shares included in the Prospectus consist of upto 22,590,361 that the Selling Stockholders may receive pursuant to the partial conversion of principal under convertible promissorynotes in the aggregate principal amount of $15,000,000 held by such Selling Stockholders. The 22,590,361 Ordinary Shares iscalculated based upon the floor price of $0.332 per share (“Floor Price”) as set forth in the convertible promissory note. Except withrespect to the Company’s par value, this prospectus supplement does not take into account the Company’s reverse stock split, whichwent effective on October 23, 2025. Specifically, this Prospectus Supplement is being filed to update and supplement the information included in the Prospectuswith certain information set forth below and contained in our Report on Form 6-K, which was submitted to the U.S. Securities andExchange Commission (the “SEC”) on October 21, 2025 (the “Form 6-K”). Accordingly, we have attached the Form 6-K to thisProspectus Supplement. Any statement contained in the Prospectus shall be deemed to be modified or superseded to the extent thatinformation in this Prospectus Supplement modifies or supersedes such statement. Capitalized terms used but not defined herein have the meanings ascribed to them in the Prospectus. This Prospectus Supplement is not complete without, and may not be utilized except in connection with, the Prospectus,including any supplements and amendments thereto. We may further amend or supplement the Prospectus and this Prospectus Supplement from time to time by filing amendmentsor supplements as required. You should read the entire Prospectus, this Prospectus Supplement and any amendments or supplementscarefully before you make your investment decision. Our Ordinary Shares are listed on The Nasdaq Capital Market under the symbol “SMX” and our public warrants are listed onThe Nasdaq Capital Market under the symbol “SMXWW”. On October 21, 2025, the closing price of our Ordinary Shares was$0.7801. Investing in our Ordinary Shares involves significant risks. You should read the section entitled “Risk Factors”beginning on page 17 of the Prospectus for a discussion of certain risk factors that you should consider before investing in ourOrdinary Shares. Neither the Securities and Exchange Commission nor any state securities commission or other regulatory body hasapproved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to thecontrary is a criminal offense. The date of this Prospectus Supplement is October 23, 2025 UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUERPURSUANT TO RULE 13a-16 OR 15d-16 UNDER THESECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41639 SMX (SECURITY MATTERS) PUBLIC LIMITED COMPANY (Exact Name of Registrant as Specified in Charter) Mespil Business Centre, Mespil HouseSussex Road, Dublin 4, IrelandTel: +353-1-920-1000(Address of Principal Executive Offices) (Zip Code) Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F. Form 20-F☒Form 40-F☐ Upon the opening of business on October 23, 2025, SMX (Security Matters) Public Limited Company’s (the “Company”)ordinary shares will begin trading on the Nasdaq Capital Market (“Nasdaq”) on a post-reverse stock split basis under the currentsymbol “SMX”. The new CUSIP number of the Company’s ordinary shares will be G8267K182 and the new ISIN code will beIE000UPDVNX9. On May 2, 2025, the Company’s Shareholders approved a proposal to amend the Company’s constitution to allow theCompany’s Board of Director’s to consolidate and/or divide all or any of the Company’s classes of shares as the Board of Directorssees fit. As such, Shareholder approval was not required to effect the reverse stock split. The Company’s Board of Directors’ fixed the split ratio at 10.89958:1, every 10.89958 ordinary shares of the Company with anominal value of $0.000000000000287 per share will be automatically combined into one (1) ordinary share with a nominal value of$0.00000000000312817946 per share. The Reverse Stock Split will reduce the number of outstanding shares of the Company from approximately 15.5 million toapproximately 1 million and will affect all outstanding ordinary shares. Every 10.89958 outstanding ordinary shares w