Entry into a Material Definitive Agreement Amendment to Credit Agreement On July 31, 2026, Celanese US Holdings LLC (“Celanese US”), a wholly-owned subsidiary of Celanese Corporation (the “Company”) entered into a First Amendment to Credit Agreement (the “Amendment”), which amends the Credit Agreement, dated as of August 11, 2025, by and among the Company, Celanese US, as borrower, certain subsidiaries of Celanese US from time to time party thereto as borrowers, each lender from time to time…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant The information included in

disclosure. Each Non-US GAAP financial measure appearing in the press release is accompanied by the most directly comparable US GAAP financial measure and is reconciled to the most comparable US GAAP financial measure in Exhibit 99.2, which includes other supplemental information of interest to investors, analysts and other parties, including the reasons why management believes such Non-US GAAP financial measures provide useful information to investors, and which is incorporated herein solely…

Other Events. On June 10, 2026, Celanese US Holdings LLC, a wholly owned subsidiary of Celanese Corporation, issued a notice of redemption for all of its outstanding 4.777% Senior Notes due July 19, 2026 (the “Notes”) pursuant to the indenture governing the Notes. The redemption is expected to occur on June 25, 2026 (the “Redemption Date”). The Notes are redeemable at a redemption price that will be equal to the sum of 100% of the principal amount of the Notes being redeemed plus accrued and…

disclosure. Each Non-US GAAP financial measure appearing in the press release is accompanied by the most directly comparable US GAAP financial measure and is reconciled to the most comparable US GAAP financial measure in Exhibit 99.2, which includes other supplemental information of interest to investors, analysts and other parties, including the reasons why management believes such Non-US GAAP financial measures provide useful information to investors, and which is incorporated herein solely…

Director — Anne P. Noonan: The Board of Directors elected Anne P. Noonan as a new director.

Director — Timothy Go: Mr. Go resigned from the Board of Directors without any disagreement with the Company.

disclosure. Each Non-US GAAP financial measure appearing in the press release is accompanied by the most directly comparable US GAAP financial measure and is reconciled to the most comparable US GAAP financial measure in Exhibit 99.2, which includes other supplemental information of interest to investors, analysts and other parties, including the reasons why management believes such Non-US GAAP financial measures provide useful information to investors, and which is incorporated herein solely…

Director — Scott M. Sutton: A director resigned to take a CEO role at another company, which is a standard board turnover event with no indication of conflict or operational impact.

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information included in

Entry into a Material Definitive Agreement. Completion of Offering of Senior Notes by Celanese US Holdings LLC On December 17, 2025, Celanese US Holdings LLC ("Celanese US" or the "Issuer"), a wholly owned subsidiary of Celanese Corporation (the "Company"), completed its registered offering of $600,000,000 aggregate principal amount of its 7.000% Senior Notes due 2031 (the "2031 Notes") and $800,000,000 aggregate principal amount of its 7.375% Senior Notes due 2034 (the "2034 Notes" and toget…

Other Events. On December 16, 2025, Celanese Corporation (the “Company”) issued a press release announcing the early results and upsize of the previously announced cash tender offers (the “Tender Offers”) to purchase up to an aggregate principal amount equal to $946,106,000 of its outstanding 6.665% Senior Notes due 2027 and up to an aggregate principal amount not to exceed $254,000,000 of its outstanding 6.850% Senior Notes due 2028. A copy of the press release is filed as Exhibit 99.1 to th…

Entry into a Material Definitive Agreement. On December 3, 2025, Celanese Corporation ("Celanese"), its wholly-owned subsidiary Celanese US Holdings LLC (the "Issuer"), and certain subsidiaries of the Issuer (together with Celanese and the Issuer, the "Company Parties"), entered into an Underwriting Agreement with BofA Securities, Inc., as representative of the other several underwriters named in Schedule A thereto, providing for the offer and sale by the Issuer of $600,000,000 aggregate prin…

Other Events. On December 2, 2025, Celanese Corporation ("Celanese") issued a press release announcing that Celanese US Holdings LLC, a direct wholly-owned subsidiary of Celanese (the "Company"), has commenced cash tender offers (the "Tender Offers") to purchase up to an aggregate principal amount not to exceed $1,000,000,000 of its outstanding (i) 6.665% Senior Notes due 2027 (the "2027 Notes") and (ii) 6.850% Senior Notes due 2028 (the "2028 Notes" and together with the 2027 Notes, the "Not…

disclosure. Each Non-US GAAP financial measure appearing in the press release is accompanied by the most directly comparable US GAAP financial measure and is reconciled to the most comparable US GAAP financial measure in Exhibit 99.2, which includes other supplemental information of interest to investors, analysts and other parties, including the reasons why management believes such Non-US GAAP financial measures provide useful information to investors, and which is incorporated herein solely…

Costs Associated with Exit or Disposal Activities. On October 28, 2025, Celanese Corporation (“Celanese” or the “Company”) announced the intended closure of its facility in Lanaken, Belgium to help streamline the Company’s production costs across its global network. Celanese’s facility in Lanaken, Belgium is an acetate tow production site. This proposed cessation is subject to a consultation process with the applicable works council and union representatives at the facility, which the Company…

Regulation FD Disclosure On October 28, 2025, Celanese Corporation (the “Company”) announced the signing of a purchase and sale agreement with Element Solutions Inc to divest the Company's Micromax® portfolio of products. Press Release A copy of the press release announcing the above-referenced transaction is furnished as Exhibit 99.1 to this Current Report on Form 8-K (this “Current Report”). Forward-Looking Statements The information set forth in this Current Report contains certain “forwar…

Entry into a Material Definitive Agreement Revolving Credit Agreement On August 11, 2025, Celanese Corporation (the “Company”) and its wholly owned subsidiary Celanese US Holdings LLC (“Celanese US”) entered into a Credit Agreement (the “Revolving Credit Agreement”) by and among the Company, Celanese US as borrower, certain subsidiaries of Celanese US from time to time party thereto as borrowers, each lender from time to time party thereto, Bank of America, N.A., as Administrative Agent, a Sw…

disclosure. Each Non-US GAAP financial measure appearing in the press release is accompanied by the most directly comparable US GAAP financial measure and is reconciled to the most comparable US GAAP financial measure in Exhibit 99.2, which includes other supplemental information of interest to investors, analysts and other parties, including the reasons why management believes such Non-US GAAP financial measures provide useful information to investors, and which is incorporated herein solely…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant The information included in

Termination of a Material Definitive Agreement The information included in

disclosure. Each Non-US GAAP financial measure appearing in the press release is accompanied by the most directly comparable US GAAP financial measure and is reconciled to the most comparable US GAAP financial measure in Exhibit 99.2, which includes other supplemental information of interest to investors, analysts and other parties, including the reasons why management believes such Non-US GAAP financial measures provide useful information to investors, and which is incorporated herein solely…

Other Events. On March 18, 2025, Celanese Corporation (the “Company”) issued a press release announcing the early results and upsize of the previously announced cash tender offers (the “Tender Offers”) to purchase up to an aggregate principal amount equal to €552,082,000 of its outstanding 4.777% Senior Notes due 2026 and up to an aggregate principal amount not to exceed $500,000,000 of its outstanding 6.415% Senior Notes due 2027. A copy of the press release is filed as Exhibit 99.1 to this…

Entry into a Material Definitive Agreement. Completion of Offerings of Senior Notes by Celanese US Holdings LLC On March 14, 2025, Celanese US Holdings LLC (“Celanese US” or the “Issuer”), a wholly owned subsidiary of Celanese Corporation (the “Company”), completed its concurrent registered offerings of $700,000,000 aggregate principal amount of its 6.500% Senior Notes due 2030 (the “2030 Notes”) and $1,100,000,000 aggregate principal amount of its 6.750% Senior Notes due 2033 (the “2033 Note…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information included in