Exhibit 4.18

AMENDMENT NO. 1 TO TAX BENEFITS PRESERVATION PLAN

This Amendment No. 1 to Tax Benefits Preservation Plan (this “Amendment”), dated as of January 21, 2021, by and between United Airlines Holdings, Inc., a Delaware corporation (the “Company”), and Computershare Trust Company, N.A., a federally chartered trust company, as rights agent (the “Rights Agent”), amends that certain Tax Benefits Preservation Plan, dated as of December 4, 2020, by and between the Company and the Rights Agent (the “Rights Agreement”). All capitalized terms used but not defined herein shall have the meanings given to such terms in the Rights Agreement.

WHEREAS, the Board has determined that it is desirable to amend the Rights Agreement as set forth herein;

WHEREAS, subject to certain limited exceptions, Section 27 of the Rights Agreement provides that the Company may, in its sole and absolute discretion, and the Rights Agent shall if the Company so directs, amend any provision of the Rights Agreement in any respect without the approval of any holders of the Rights;

WHEREAS, this Amendment is permitted by Section 27 of the Rights Agreement; and

WHEREAS, pursuant to Section 27 of the Rights Agreement, the Company hereby directs that the Rights Agreement shall be amended as set forth in this Amendment.

NOW THEREFORE, in consideration of the foregoing premises and mutual covenants and agreements set forth herein, and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Company and the Rights Agent hereby agree as follows:

Section 1. Amendment to Section 1. The definition of “Warrant Agreements” set forth in Section 1 of the Rights Agreement is hereby amended and restated in its entirety as follows:

“Warrant Agreements” shall mean (i) that certain Warrant Agreement, dated as of April 20, 2020, between the Company and the United States Department of the Treasury, (ii) that certain Warrant Agreement, dated as of September 28, 2020, between the Company and the United States Department of the Treasury and (iii) that certain Warrant Agreement, dated as of January 15, 2021, between the Company and the United States Department of the Treasury, as each such agreement may be amended from time to time in accordance with its terms.

Section 2. Effective Date; Certification. This Amendment shall be deemed effective as of the date first written above, as if executed on such date. The duly authorized officer of the Company executing this Amendment hereby certifies to the Rights Agent that the amendment to the Rights Agreement set forth in this Amendment is in compliance with Section 27 of the Rights

Agreement and the certification contained in this Section 2 shall constitute the certification required by Section 27 of the Rights Agreement.

Section 3. Governing Law. This Amendment shall be deemed to be a contract made under the laws of the State of Delaware and for all purposes shall be governed by and construed in accordance with the laws of such State applicable to contracts to be made and performed entirely within such State.

Section 4. Severability. If any term, provision, covenant or restriction of this Amendment is held by a court of competent jurisdiction or other authority to be invalid, void or unenforceable, the remainder of the terms, provisions, covenants and restrictions of this Amendment shall remain in full force and effect and shall in no way be affected, impaired or invalidated. If any such excluded term, provision, covenant or restriction shall affect the rights, immunities, duties or obligations of the Rights Agent in an adverse manner, then the Rights Agent shall be entitled to resign immediately upon written notice to the Company.

Section 5. Counterparts. This Amendment may be executed in any number of counterparts and each of such counterparts shall for all purposes be deemed to be an original, and all such counterparts shall together constitute but one and the same instrument. Delivery of an executed signature page of this Amendment by facsimile or other customary means of electronic transmission (e.g., “pdf”) shall be as effective as delivery of a manually executed counterpart hereof.

Section 6. No Modification. Except as expressly set forth herein, this Amendment shall not by implication or otherwise alter, modify, amend or in any way affect any of the terms, conditions, obligations, covenants or agreements contained in the Rights Agreement, all of which are ratified and affirmed in all respects and shall continue in full force and effect.

Section 7. Headings. The headings of the sections of this Amendment have been inserted for convenience of reference only and shall in no way restrict or otherwise modify any of the terms or provisions hereof.

[Signature Page Follows]

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed as of the date and year first above written.

UNITED AIRLINES HOLDINGS, INC.

By: /s/ Gerald Laderman

Name: Gerald Laderman

Title: Executive Vice President and Chief Financial Officer

COMPUTERSHARE TRUST COMPANY, N.A.

By:  /s/ Fred Papenmeier

Name: Fred Papenmeier

Title: Vice President & Manager

Amendment No. 1 to Tax Benefits Preservation Plan