As filed with the Securities and Exchange Commission on January 23, 2026

Registration No. 333-292677 

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION 

Washington, D.C. 20549

AMENDMENT NO. 1 

TO

FORM F-3

REGISTRATION STATEMENT UNDER
THE SECURITIES ACT OF 1933

Arqit Quantum Inc. 

(Exact name of registrant as specified in its charter)

Arqit Quantum Inc. 

2nd Floor, 3 Orchard Place 

London SW1H 0BF 

United Kingdom

Telephone: (+44) (0) 20 3917 0155

(Address and telephone number of Registrant’s principal executive offices)

Arqit Inc. 

1209 Orange Street 

Wilmington, DE 19801

Telephone: (302) 658-7581

(Name, address, and telephone number of agent for service)

Copies of all correspondence to:

If only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. ¨

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933,

check the following box. x

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

If this Form is a registration statement pursuant to General Instruction I.C. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ¨

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.C. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ¨

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933.

Emerging growth company x

If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP, 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 7(a)(2)(B) of the Securities Act. ¨

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment that specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until the registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

This Amendment No. 1 is being filed to amend the Registration Statement on Form F-3 (File No. 333- 292677) originally filed by the registrant on January 12, 2026 to (i) modify the amount of unsold securities to be included on the Registration Statement pursuant to Rule 415(a)(6) under the Securities Act of 1933, as amended, that were registered on a previously filed registration statement, as indicated in Exhibit 107 to this Amendment; and (ii) update the exhibit index set forth in Item 16. Accordingly, this Amendment No. 1 consists only of the facing page, this explanatory note, Part II of the Registration Statement, the signature page to the Registration Statement, and the exhibit being filed with this Amendment No. 1. The remainder of the Registration Statement, including the prospectus, is unchanged and has been omitted.

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Cayman Islands law does not limit the extent to which a company’s articles of association may provide for indemnification of officers and directors, except to the extent any such provision may be held by the Cayman Islands courts to be contrary to public policy, such as to provide indemnification against willful default, willful neglect, civil fraud or the consequences of committing a crime. Our Amended and Restated Memorandum and Articles of Association (our “articles of association”) permit indemnification of officers and directors for any liability, action, proceeding, claim, demand, costs damages or expenses, including legal expenses, incurred in their capacities as such unless such liability (if any) arises from actual fraud, willful neglect or willful default which may attach to such directors or officers. This standard of conduct is generally the same as permitted under the Delaware General Corporation Law for a Delaware corporation. In addition, we have entered into indemnification agreements with our directors and senior executive officers that provide such persons with additional indemnification beyond that provided in our articles of association.

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to our directors, officers or persons controlling us under the foregoing provisions, we have been informed that, in the opinion of the SEC, such indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable.

provided, however, that paragraphs (a)(1)(i), (a)(1)(ii), and (a)(1)(iii) of this section do not apply if the registration statement is on Form F-3 and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, that are incorporated by reference in the registration statement, or, as to a registration statement on Form F-3, is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form F-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in London, United Kingdom, on January 23, 2026.

Pursuant to the requirements of the Securities Act of 1933, as amended, this registration statement has been signed below by the following persons in the capacities and on the dates indicated.

AUTHORIZED REPRESENTATIVE

Pursuant to the requirement of the Securities Act of 1933, as amended, the undersigned, the duly authorized representative in the United States of Arqit Quantum Inc. has signed this registration statement on January 23, 2026.