Southwest Gas Holdings, Inc.

Southwest Gas Holdings, Inc. (“Southwest Gas Holdings” or the “Company”) is filing this Current Report on Form 8-K to report the Audit Committee of the Board of Directors of the Company’s (the “Audit Committee’s”) conclusion that the Company’s unaudited Condensed Consolidated Financial Statements as of June 30, 2025 and September 30, 2025, and for the three and six months ended June 30, 2025 and three and nine months ended September 30, 2025 (collectively, the “Restated Periods”) should no longer be relied upon, as discussed further below.

In connection with the preparation of the Company’s upcoming Annual Report on Form 10-K for the year ended December 31, 2025 (the “2025 Form 10-K”), management identified errors related to the estimated deferred income tax liabilities for state income taxes. The errors do not impact the Company’s previously communicated guidance metrics. The Company reaffirms its guidance for 2025 net income as well as the expected compound annual growth rates (“CAGR”) for Southwest Gas Corporation net income and rate base for the 2025-2029 period.1 The Company does not expect any impact on previously reported operating margin, cash flows, credit metrics, historical state income tax returns, cash income taxes paid, nor compliance with debt covenants for any previous interim periods or years related to these errors. The Company expects that there will be a de minimis effect on annual cash income tax payments in future years.

The issues result from not timely updating estimated apportionment rates to reflect certain events. For Southwest Gas Corporation, the errors date back to the formation of Southwest Gas Holdings in 2017, when Southwest Gas Corporation and Centuri Holdings, Inc. (“Centuri”) became wholly-owned subsidiaries of Southwest Gas Holdings. These errors were determined to be not material to any previously issued Southwest Gas Corporation financial statements. Although these financial statements can still be relied upon, Southwest Gas Corporation plans to revise the historical financial statements due to the cumulative effect of correcting the deferred income tax error in the 2025 Form 10-K. For the Company, the errors arose following the Company’s sale of shares of Centuri’s common stock in the second and third quarters of 2025, which resulted in the tax deconsolidation of Centuri, as discussed further in Item 4.02 below.