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of Contents](#i5f73e41dadc741329774599f12c4776d_7)                                [Index to Financial Statements](#i5f73e41dadc741329774599f12c4776d_337)\n\nUNITED STATES\n\nSECURITIES AND EXCHANGE COMMISSION\n\nWashington, D.C. 20549\n\nFORM 10-K\n\n☑ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d)\n\nOF THE SECURITIES EXCHANGE ACT OF 1934\n\nFor the Fiscal Year Ended December 31, 2025\n\nOR\n\n☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d)\n\nOF THE SECURITIES EXCHANGE ACT OF 1934\n\nFor the Transition Period from            to           \n\nCommission\nFile NumberRegistrant,\nState of Incorporation,\nAddress and Telephone NumberI.R.S. Employer\nIdentification No.\n\n1-3526The Southern Company58-0690070\n\n(A Delaware Corporation)\n\n30 Ivan Allen Jr. Boulevard, N.W.\n\nAtlanta, Georgia 30308\n\n(404) 506-5000\n\n1-3164Alabama Power Company63-0004250\n\n(An Alabama Corporation)\n\n600 North 18th Street\n\nBirmingham, Alabama 35203\n\n(205) 257-1000\n\n1-6468Georgia Power Company58-0257110\n\n(A Georgia Corporation)\n\n241 Ralph McGill Boulevard, N.E.\n\nAtlanta, Georgia 30308\n\n(404) 506-6526\n\n001-11229Mississippi Power Company64-0205820\n\n(A Mississippi Corporation)\n\n2992 West Beach Boulevard\n\nGulfport, Mississippi 39501\n\n(228) 864-1211\n\n001-37803Southern Power Company58-2598670\n\n(A Delaware Corporation)\n\n30 Ivan Allen Jr. Boulevard, N.W.\n\nAtlanta, Georgia 30308\n\n(404) 506-5000\n\n1-14174Southern Company Gas58-2210952\n\n(A Georgia Corporation)\n\nTen Peachtree Place, N.E.\n\nAtlanta, Georgia 30309\n\n(404) 584-4000\n\n    [Table of Contents](#i5f73e41dadc741329774599f12c4776d_7)                                [Index to Financial Statements](#i5f73e41dadc741329774599f12c4776d_337)\n\nSecurities registered pursuant to Section 12(b) of the Act:\n\nRegistrantTitle of Each ClassTrading\nSymbol(s)Name of Each Exchange\non Which Registered\n\nThe Southern CompanyCommon Stock, par value $5 per shareSONew York Stock Exchange\n\n(NYSE)\n\nThe Southern CompanySeries 2017B 5.25% Junior Subordinated Notes due 2077SOJCNYSE\n\nThe Southern CompanySeries 2020A 4.95% Junior Subordinated Notes due 2080SOJDNYSE\n\nThe Southern CompanySeries 2020C 4.20% Junior Subordinated Notes due 2060SOJENYSE\n\nThe Southern CompanySeries 2021B 1.875% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due 2081SO 81NYSE\n\nThe Southern Company\n\nSeries 2025A 6.50% Junior Subordinated Notes due 2085\n\nSOJF\n\nNYSE\n\nThe Southern Company\n\n2025 Series A Corporate Units\n\nSOMN\n\nNYSE\n\nGeorgia Power CompanySeries 2017A 5.00% Junior Subordinated Notes due 2077GPJANYSE\n\nSouthern Power CompanySeries 2016B 1.850% Senior Notes due 2026SO/26ANYSE\n\nSecurities registered pursuant to Section 12(g) of the Act: None\n\nIndicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.\n\nRegistrantYesNo\n\nThe Southern CompanyX\n\nAlabama Power CompanyX\n\nGeorgia Power CompanyX\n\nMississippi Power CompanyX\n\nSouthern Power CompanyX\n\nSouthern Company GasX\n\nIndicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ¨ No x (Response applicable to all registrants.)\n\nIndicate by check mark whether the registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days. Yes x No ¨\n\nIndicate by check mark whether the registrants have submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrants were required to submit such files). Yes x No ¨\n\nIndicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of \"large accelerated filer,\" \"accelerated filer,\" \"smaller reporting company,\" and \"emerging growth company\" in Rule 12b-2 of the Exchange Act.\n\nRegistrantLarge Accelerated FilerAccelerated\nFilerNon-accelerated FilerSmaller\nReporting\nCompanyEmerging Growth Company\n\nThe Southern CompanyX\n\nAlabama Power CompanyX\n\nGeorgia Power CompanyX\n\nMississippi Power CompanyX\n\nSouthern Power CompanyX\n\nSouthern Company GasX\n\nIf an emerging growth company, 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 13(a) of the Exchange Act. ☐\n\n    [Table of Contents](#i5f73e41dadc741329774599f12c4776d_7)                                [Index to Financial Statements](#i5f73e41dadc741329774599f12c4776d_337)\n\nIndicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.\n\nRegistrantYesNo\n\nThe Southern CompanyX\n\nAlabama Power CompanyX\n\nGeorgia Power CompanyX\n\nMississippi Power CompanyX\n\nSouthern Power CompanyX\n\nSouthern Company GasX\n\nIf securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐\n\nIndicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant's executive officers during the relevant recovery period pursuant to § 240.10D-1(b). ☐\n\nIndicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No x (Response applicable to all registrants.)\n\nAggregate market value of The Southern Company's common stock held by non-affiliates of The Southern Company at June 30, 2025: $101.0 billion. All of the common stock of the other registrants is held by The Southern Company. A description of each registrant's common stock follows:\n\nRegistrantDescription of\nCommon StockShares Outstanding at January 31, 2026\n\nThe Southern CompanyPar Value $5 Per Share1,119,391,291 \n\nAlabama Power CompanyPar Value $40 Per Share30,537,500 \n\nGeorgia Power CompanyWithout Par Value9,261,500 \n\nMississippi Power CompanyWithout Par Value1,121,000 \n\nSouthern Power CompanyPar Value $0.01 Per Share1,000 \n\nSouthern Company GasPar Value $0.01 Per Share100 \n\nDocuments incorporated by reference: specified portions of The Southern Company's Definitive Proxy Statement on Schedule 14A relating to the 2026 Annual Meeting of Stockholders are incorporated by reference into PART III.\n\nEach of Alabama Power Company, Georgia Power Company, Mississippi Power Company, Southern Power Company, and Southern Company Gas meets the conditions set forth in General Instructions I(1)(a) and (b) of Form 10-K and is therefore filing this Form 10-K with the reduced disclosure format specified in General Instructions I(2)(b), (c), and (d) of Form 10-K.\n\nThis combined Form 10-K is separately filed by The Southern Company, Alabama Power Company, Georgia Power Company, Mississippi Power Company, Southern Power Company, and Southern Company Gas. Information contained herein relating to any individual registrant is filed by such registrant on its own behalf. Each registrant makes no representation as to information relating to the other registrants.\n\n    [Table of Contents](#i5f73e41dadc741329774599f12c4776d_7)                                [Index to Financial Statements](#i5f73e41dadc741329774599f12c4776d_337)\n\nTable of Contents\n\nPage\n\n[Definitions](#i5f73e41dadc741329774599f12c4776d_10)\n\n[ii](#i5f73e41dadc741329774599f12c4776d_10)\n\n[Cautionary Statement Regarding Forward-Looking Information](#i5f73e41dadc741329774599f12c4776d_13)\n\n[vi](#i5f73e41dadc741329774599f12c4776d_13)\n\n[PART I](#i5f73e41dadc741329774599f12c4776d_16)\n\n[Item 1](#i5f73e41dadc741329774599f12c4776d_19)\n\n[Business](#i5f73e41dadc741329774599f12c4776d_19)\n\nI-[1](#i5f73e41dadc741329774599f12c4776d_19)\n\n[The Southern Company System](#i5f73e41dadc741329774599f12c4776d_22)\n\nI-[1](#i5f73e41dadc741329774599f12c4776d_22)\n\n[Construction Programs](#i5f73e41dadc741329774599f12c4776d_31)\n\nI-[4](#i5f73e41dadc741329774599f12c4776d_31)\n\n[Financing Programs](#i5f73e41dadc741329774599f12c4776d_34)\n\nI-[5](#i5f73e41dadc741329774599f12c4776d_34)\n\n[Fuel Supply](#i5f73e41dadc741329774599f12c4776d_37)\n\nI-[5](#i5f73e41dadc741329774599f12c4776d_37)\n\n[Territory](#i5f73e41dadc741329774599f12c4776d_43)[and Customers](#i5f73e41dadc741329774599f12c4776d_43)[Served by the Southern Company System](#i5f73e41dadc741329774599f12c4776d_43)\n\nI-[6](#i5f73e41dadc741329774599f12c4776d_43)\n\n[Competition](#i5f73e41dadc741329774599f12c4776d_49)\n\nI-[8](#i5f73e41dadc741329774599f12c4776d_49)\n\n[Seasonality](#i5f73e41dadc741329774599f12c4776d_55)\n\nI-[10](#i5f73e41dadc741329774599f12c4776d_55)\n\n[Regulation](#i5f73e41dadc741329774599f12c4776d_58)\n\nI-[10](#i5f73e41dadc741329774599f12c4776d_58)\n\n[Rate Matters](#i5f73e41dadc741329774599f12c4776d_61)\n\nI-[11](#i5f73e41dadc741329774599f12c4776d_61)\n\n[Human Capital](#i5f73e41dadc741329774599f12c4776d_76)\n\nI-[13](#i5f73e41dadc741329774599f12c4776d_76)\n\n[Item 1A](#i5f73e41dadc741329774599f12c4776d_79)\n\n[Risk Factors](#i5f73e41dadc741329774599f12c4776d_79)\n\nI-[15](#i5f73e41dadc741329774599f12c4776d_79)\n\n[Item 1B](#i5f73e41dadc741329774599f12c4776d_82)\n\n[Unresolved Staff Comments](#i5f73e41dadc741329774599f12c4776d_82)\n\nI-[28](#i5f73e41dadc741329774599f12c4776d_82)\n\n[Item 1C](#i5f73e41dadc741329774599f12c4776d_85)\n\n[Cybersecurity](#i5f73e41dadc741329774599f12c4776d_85)\n\nI-[28](#i5f73e41dadc741329774599f12c4776d_85)\n\n[Item 2](#i5f73e41dadc741329774599f12c4776d_88)\n\n[Properties](#i5f73e41dadc741329774599f12c4776d_88)\n\nI-[32](#i5f73e41dadc741329774599f12c4776d_88)\n\n[Item 3](#i5f73e41dadc741329774599f12c4776d_94)\n\n[Legal Proceedings](#i5f73e41dadc741329774599f12c4776d_94)\n\nI-[38](#i5f73e41dadc741329774599f12c4776d_94)\n\n[Item 4](#i5f73e41dadc741329774599f12c4776d_97)\n\n[Mine Safety Disclosures](#i5f73e41dadc741329774599f12c4776d_97)\n\nI-[39](#i5f73e41dadc741329774599f12c4776d_97)\n\n[Information about Our Executive Officers – Southern Company](#i5f73e41dadc741329774599f12c4776d_100)\n\nI-[40](#i5f73e41dadc741329774599f12c4776d_100)\n\n[PART II](#i5f73e41dadc741329774599f12c4776d_103)\n\n[Item 5](#i5f73e41dadc741329774599f12c4776d_106)\n\n[Market for Registrants' Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities](#i5f73e41dadc741329774599f12c4776d_106)\n\nII-[1](#i5f73e41dadc741329774599f12c4776d_106)\n\n[Item 6](#i5f73e41dadc741329774599f12c4776d_106)\n\n[Reserved](#i5f73e41dadc741329774599f12c4776d_106)\n\n[II-1](#i5f73e41dadc741329774599f12c4776d_106)\n\n[Item 7](#i5f73e41dadc741329774599f12c4776d_109)\n\n[Management's Discussion and Analysis of Financial Condition and Results of Operations](#i5f73e41dadc741329774599f12c4776d_109)\n\nII-[2](#i5f73e41dadc741329774599f12c4776d_109)\n\n[Item 7A](#i5f73e41dadc741329774599f12c4776d_109)\n\n[Quantitative and Qualitative Disclosures about Market Risk](#i5f73e41dadc741329774599f12c4776d_109)\n\nII-[2](#i5f73e41dadc741329774599f12c4776d_109)\n\n[Item 8](#i5f73e41dadc741329774599f12c4776d_337)\n\n[Financial Statements and Supplementary Data](#i5f73e41dadc741329774599f12c4776d_337)\n\nII-[68](#i5f73e41dadc741329774599f12c4776d_337)\n\n[Item 9](#i5f73e41dadc741329774599f12c4776d_721)\n\n[Changes in and Disagreements with Accountants on Accounting and Financial Disclosure](#i5f73e41dadc741329774599f12c4776d_721)\n\nII-[253](#i5f73e41dadc741329774599f12c4776d_721)\n\n[Item 9A](#i5f73e41dadc741329774599f12c4776d_724)\n\n[Controls and Procedures](#i5f73e41dadc741329774599f12c4776d_724)\n\nII-[253](#i5f73e41dadc741329774599f12c4776d_724)\n\n[Item 9B](#i5f73e41dadc741329774599f12c4776d_724)\n\n[Other Information](#i5f73e41dadc741329774599f12c4776d_724)\n\nII-[253](#i5f73e41dadc741329774599f12c4776d_724)\n\n[Item 9C](#i10f733b28c8243748e2a84ada00346f1_4303)\n\n[Disclosure Regarding Foreign Jurisdictions that Prevent Inspections](#i10f733b28c8243748e2a84ada00346f1_4303)\n\n[II-](#i5f73e41dadc741329774599f12c4776d_721)[254](#i10f733b28c8243748e2a84ada00346f1_4303)\n\n[PART III](#i5f73e41dadc741329774599f12c4776d_748)\n\n[Item 10](#i5f73e41dadc741329774599f12c4776d_748)\n\n[Directors, Executive Officers and Corporate Governance](#i5f73e41dadc741329774599f12c4776d_748)\n\nIII-[1](#i5f73e41dadc741329774599f12c4776d_748)\n\n[Item 11](#i5f73e41dadc741329774599f12c4776d_748)\n\n[Executive Compensation](#i5f73e41dadc741329774599f12c4776d_748)\n\nIII-[1](#i5f73e41dadc741329774599f12c4776d_748)\n\n[Item 12](#i5f73e41dadc741329774599f12c4776d_748)\n\n[Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters](#i5f73e41dadc741329774599f12c4776d_748)\n\nIII-[1](#i5f73e41dadc741329774599f12c4776d_748)\n\n[Item 13](#i5f73e41dadc741329774599f12c4776d_748)\n\n[Certain Relationships and Related Transactions, and Director Independence](#i5f73e41dadc741329774599f12c4776d_748)\n\nIII-[1](#i5f73e41dadc741329774599f12c4776d_748)\n\n[Item 14](#i5f73e41dadc741329774599f12c4776d_754)\n\n[Principal Accountant Fees and Services](#i5f73e41dadc741329774599f12c4776d_754)\n\nIII-[2](#i5f73e41dadc741329774599f12c4776d_754)\n\n[PART IV](#i5f73e41dadc741329774599f12c4776d_757)\n\n[Item 15](#i5f73e41dadc741329774599f12c4776d_760)\n\n[Exhibits and Financial Statement Schedules](#i5f73e41dadc741329774599f12c4776d_760)\n\nIV-[1](#i5f73e41dadc741329774599f12c4776d_760)\n\n[Item 16](#i5f73e41dadc741329774599f12c4776d_760)\n\n[Form 10-K Summary](#i5f73e41dadc741329774599f12c4776d_760)\n\nIV-[1](#i5f73e41dadc741329774599f12c4776d_760)\n\n[Signatures](#i5f73e41dadc741329774599f12c4776d_769)\n\ni\n\n    [Table of Contents](#i5f73e41dadc741329774599f12c4776d_7)                                [Index to Financial Statements](#i5f73e41dadc741329774599f12c4776d_337)\n\nDEFINITIONS\n\nWhen used in this Form 10-K, the following terms will have the meanings indicated.\n\nTermMeaning\n\n2022 ARP\n\nGeorgia Power's Alternate Rate Plan approved by the Georgia PSC in 2022 for the years 2023 through 2025\n\n2023 IRP Update\n\nGeorgia Power's updated IRP filed in 2023 and approved by the Georgia PSC in April 2024 as modified by a stipulation among Georgia Power, the staff of the Georgia PSC, and certain intervenors\n\nAFUDCAllowance for funds used during construction\n\nAGL Services Company\n\nAGL Services Company, Inc., the Southern Company Gas system service company and a wholly-owned subsidiary of Southern Company Gas\n\nAlabama PowerAlabama Power Company\n\nAMEAAlabama Municipal Electric Authority\n\nAmended and Restated Loan Guarantee Agreement\nLoan guarantee agreement entered into by Georgia Power with the DOE in 2014, as amended and restated in 2019, under which the proceeds of borrowings were used to reimburse Georgia Power for Eligible Project Costs incurred in connection with its construction of Plant Vogtle Units 3 and 4\n\nAOCIAccumulated other comprehensive income\n\nAROAsset retirement obligation\n\nASUAccounting Standards Update\n\nAtlanta Gas LightAtlanta Gas Light Company, a wholly-owned subsidiary of Southern Company Gas\n\nBcfBillion cubic feet\n\nCAMT\n\nCorporate alternative minimum tax\n\nCCNCertificate of convenience and necessity\n\nCCRCoal combustion residuals\n\nCCR RuleDisposal of Coal Combustion Residuals from Electric Utilities final rule published by the EPA in 2015\n\nChattanooga GasChattanooga Gas Company, a wholly-owned subsidiary of Southern Company Gas\n\nClean Air ActClean Air Act Amendments of 1990\n\nCO2\nCarbon dioxide\n\nCODCommercial operation date\n\nCODM\n\nChief operating decision maker\n\nCooperative EnergyElectric generation and transmission cooperative in Mississippi\n\nCPCNCertificate of public convenience and necessity\n\nCWIPConstruction work in progress\n\nDalton\nCity of Dalton, Georgia, an incorporated municipality in the state of Georgia, acting by and through its Board of Water, Light, and Sinking Fund Commissioners\n\nDalton PipelineA pipeline facility in Georgia in which Southern Company Gas has a 50% undivided ownership interest\n\nDOEU.S. Department of Energy\n\nECCRGeorgia Power's Environmental Compliance Cost Recovery tariff\n\nECO PlanMississippi Power's environmental compliance overview plan\n\nELGEffluent limitations guidelines\n\nEligible Project CostsCertain costs of construction relating to Plant Vogtle Units 3 and 4 that are eligible for financing under the loan guarantee program established under Title XVII of the Energy Policy Act of 2005\n\nEMCElectric membership corporation\n\nEPAU.S. Environmental Protection Agency\n\nFASBFinancial Accounting Standards Board\n\nFCCFederal Communications Commission\n\nFERCFederal Energy Regulatory Commission\n\nFFBFederal Financing Bank\n\nFFB Credit FacilitiesNote purchase agreements among the DOE, Georgia Power, and the FFB and related promissory notes which provide for two multi-advance term loan facilities\n\nii\n\n    [Table of Contents](#i5f73e41dadc741329774599f12c4776d_7)                                [Index to Financial Statements](#i5f73e41dadc741329774599f12c4776d_337)\n\nDEFINITIONS\n\n(continued)\n\nTermMeaning\n\nFitchFitch Ratings, Inc.\n\nFP&LFlorida Power and Light Company\n\nGAAPU.S. generally accepted accounting principles\n\nGeorgia PowerGeorgia Power Company\n\nGHGGreenhouse gas\n\nGRAMAtlanta Gas Light's Georgia Rate Adjustment Mechanism\n\nGW\n\nGigawatt\n\nHeating Degree DaysA measure of weather, calculated when the average daily temperatures are less than 65 degrees Fahrenheit\n\nHeating SeasonThe period from November through March when Southern Company Gas' natural gas usage and operating revenues are generally higher\n\nHLBVHypothetical liquidation at book value\n\nIBEWInternational Brotherhood of Electrical Workers\n\nIGCCIntegrated coal gasification combined cycle, the technology originally approved for Mississippi Power's Kemper County energy facility\n\nIICIntercompany Interchange Contract\n\nIllinois CommissionIllinois Commerce Commission\n\nInternal Revenue CodeInternal Revenue Code of 1986, as amended\n\nIPPIndependent power producer\n\nIRA\n\nInflation Reduction Act of 2022\n\nIRPIntegrated resource plan\n\nIRSInternal Revenue Service\n\nITCInvestment tax credit\n\nKWKilowatt\n\nKWHKilowatt-hour\n\nLIFOLast-in, first-out\n\nLNGLiquefied natural gas\n\nLTSALong-term service agreement\n\nMarketersMarketers selling retail natural gas in Georgia and certificated by the Georgia PSC\n\nMEAG PowerMunicipal Electric Authority of Georgia\n\nMississippi PowerMississippi Power Company\n\nmmBtuMillion British thermal units\n\nMoody'sMoody's Investors Service, Inc.\n\nMPUSMississippi Public Utilities Staff\n\nMRAMunicipal and Rural Associations\n\nMWMegawatt\n\nnatural gas distribution utilitiesSouthern Company Gas' natural gas distribution utilities (Nicor Gas, Atlanta Gas Light, Virginia Natural Gas, and Chattanooga Gas)\n\nNCCRGeorgia Power's Nuclear Construction Cost Recovery tariff\n\nNDRAlabama Power's Natural Disaster Reserve\n\nNicor GasNorthern Illinois Gas Company, a wholly-owned subsidiary of Southern Company Gas\n\nNRCU.S. Nuclear Regulatory Commission\n\nNYMEXNew York Mercantile Exchange, Inc.\n\nNYSENew York Stock Exchange\n\nOBBB\n\nOne Big Beautiful Bill Act\n\nOCIOther comprehensive income\n\nOPCOglethorpe Power Corporation (an EMC)\n\nOTCOver-the-counter\n\niii\n\n    [Table of Contents](#i5f73e41dadc741329774599f12c4776d_7)                                [Index to Financial Statements](#i5f73e41dadc741329774599f12c4776d_337)\n\nDEFINITIONS\n\n(continued)\n\nTermMeaning\n\nPEPMississippi Power's Performance Evaluation Plan\n\nPowerSecurePowerSecure, Inc., a wholly-owned subsidiary of Southern Company\n\nPowerSouthPowerSouth Energy Cooperative\n\nPPAPower purchase agreements, as well as, for Southern Power, contracts for differences that provide the owner of a renewable facility a certain fixed price for the electricity sold to the grid\n\nPSCPublic Service Commission\n\nPTCProduction tax credit\n\nRate CNPAlabama Power's Rate Certificated New Plant, consisting of Rate CNP New Plant, Rate CNP Compliance, Rate CNP PPA, and Rate CNP Depreciation\n\nRate ECRAlabama Power's Rate Energy Cost Recovery\n\nRate NDRAlabama Power's Rate Natural Disaster Reserve\n\nRate RSEAlabama Power's Rate Stabilization and Equalization\n\nRegistrantsSouthern Company, Alabama Power, Georgia Power, Mississippi Power, Southern Power Company, and Southern Company Gas\n\nRFP\n\nRequest for proposals\n\nROEReturn on equity\n\nS&PS&P Global Ratings, a division of S&P Global Inc.\n\nSAVESteps to Advance Virginia's Energy, an infrastructure replacement program at Virginia Natural Gas\n\nSCSSouthern Company Services, Inc., the Southern Company system service company and a wholly-owned subsidiary of Southern Company\n\nSECU.S. Securities and Exchange Commission\n\nSEGCOSouthern Electric Generating Company, 50% owned by each of Alabama Power and Georgia Power\n\nSEPASoutheastern Power Administration\n\nSNGSouthern Natural Gas Company, L.L.C., a pipeline system in which Southern Company Gas has a 50% ownership interest\n\nSOFRSecured Overnight Financing Rate\n\nSouthern CompanyThe Southern Company\n\nSouthern Company GasSouthern Company Gas and its subsidiaries\n\nSouthern Company Gas Capital\nSouthern Company Gas Capital Corporation, a wholly-owned subsidiary of Southern Company Gas\n\nSouthern Company power poolThe operating arrangement whereby the integrated generating resources of the traditional electric operating companies and Southern Power (excluding subsidiaries) are subject to joint commitment and dispatch in order to serve their combined load obligations\n\nSouthern Company systemSouthern Company, the traditional electric operating companies, Southern Power, Southern Company Gas, SEGCO, Southern Nuclear, SCS, Southern Linc, PowerSecure, and other subsidiaries\n\nSouthern HoldingsSouthern Company Holdings, Inc., a wholly-owned subsidiary of Southern Company\n\nSouthern LincSouthern Communications Services, Inc., a wholly-owned subsidiary of Southern Company, doing business as Southern Linc\n\nSouthern NuclearSouthern Nuclear Operating Company, Inc., a wholly-owned subsidiary of Southern Company\n\nSouthern PowerSouthern Power Company and its subsidiaries\n\nSouthStarSouthStar Energy Services, LLC (a Marketer), a wholly-owned subsidiary of Southern Company Gas\n\nSP SolarSP Solar Holdings I, LP, a limited partnership indirectly owning substantially all of Southern Power's solar and battery energy storage facilities, in which Southern Power has a 67% ownership interest\n\nSP Wind\nSP Wind Holdings II, LLC, a holding company owning a portfolio of eight operating wind facilities and wholly-owned by Southern Power as of December 31, 2025, was previously in a tax equity arrangement where Southern Power was the controlling partner through December 31, 2025\n\niv\n\n    [Table of Contents](#i5f73e41dadc741329774599f12c4776d_7)                                [Index to Financial Statements](#i5f73e41dadc741329774599f12c4776d_337)\n\nDEFINITIONS\n\n(continued)\n\nTermMeaning\n\nSRRMississippi Power's System Restoration Rider, a tariff for retail property damage cost recovery and reserve\n\nSubsidiary RegistrantsAlabama Power, Georgia Power, Mississippi Power, Southern Power, and Southern Company Gas\n\nTax Reform LegislationThe Tax Cuts and Jobs Act, which became effective on January 1, 2018\n\ntraditional electric operating companiesAlabama Power, Georgia Power, and Mississippi Power\n\nU.S. Treasury\n\nU.S. Department of the Treasury\n\nVIEVariable interest entity\n\nVirginia CommissionVirginia State Corporation Commission\n\nVirginia Natural GasVirginia Natural Gas, Inc., a wholly-owned subsidiary of Southern Company Gas\n\nVogtle Owners\nGeorgia Power, OPC, MEAG Power, and Dalton\n\nv\n\n    [Table of Contents](#i5f73e41dadc741329774599f12c4776d_7)                                [Index to Financial Statements](#i5f73e41dadc741329774599f12c4776d_337)\n\nCAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION\n\nThis Annual Report on Form 10-K contains forward-looking statements. Forward-looking statements include, among other things, statements concerning regulated rates, the strategic goals for the business, customer and sales growth, economic conditions, including interest rates, tariffs, and inflation, cost recovery and other rate actions, projected equity ratios, current and proposed environmental regulations and related compliance plans and estimated expenditures, GHG emissions reduction goals, pending or potential litigation matters, access to sources of capital, projections for the qualified pension plans, postretirement benefit plans, and nuclear decommissioning trust fund contributions, financing activities, completion dates and costs of construction projects, filings with state and federal regulatory authorities, federal and state income tax benefits, estimated sales and purchases under power sale and purchase agreements, and estimated construction plans and expenditures. In some cases, forward-looking statements can be identified by terminology such as \"may,\" \"will,\" \"could,\" \"would,\" \"should,\" \"expects,\" \"plans,\" \"anticipates,\" \"believes,\" \"estimates,\" \"projects,\" \"predicts,\" \"potential,\" or \"continue\" or the negative of these terms or other similar terminology. There are various factors that could cause actual results to differ materially from those suggested by the forward-looking statements; accordingly, there can be no assurance that such indicated results will be realized. These factors include:\n\n•the impact of recent and future federal and state legal and regulatory changes, including tax, environmental, and other laws and regulations to which Southern Company and its subsidiaries are subject, as well as changes in application of existing laws, regulations, and guidance;\n\n•the extent and timing of costs and legal requirements related to CCR;\n\n•current and future litigation or regulatory investigations, proceedings, or inquiries, including litigation related to the Kemper County energy facility;\n\n•the effects, extent, and timing of the entry of additional competition in the markets in which Southern Company's subsidiaries operate, including from the development and deployment of alternative energy sources;\n\n•variations in demand for electricity and natural gas, including uncertainties related to projected significant growth in electricity demand driven primarily by data centers and other large load customers, and the related requirement for substantial new generation and transmission investments, creating capital access and revenue recovery risks for the traditional electric operating companies;\n\n•customer affordability matters;\n\n•available sources and costs of natural gas and other fuels and commodities;\n\n•the ability to complete necessary or desirable pipeline expansion or infrastructure projects, limits on pipeline capacity, public and policymaker support for such projects, and operational interruptions to natural gas distribution and transmission activities;\n\n•transmission constraints;\n\n•the ability to control costs and avoid cost and schedule overruns during the development, construction, and operation of facilities or other projects due to challenges which include, but are not limited to, changes in labor costs, availability, and productivity; challenges with the management of contractors or vendors; subcontractor performance; adverse weather conditions; shortages, delays, increased costs, or inconsistent quality of equipment, materials, and labor; contractor or supplier delay; the impacts of inflation and trade policies (including tariffs and other trade measures) of the United States and other countries; delays due to judicial or regulatory action; nonperformance under construction, operating, or other agreements; operational readiness, including specialized operator training and required site safety programs; engineering or design problems or any remediation related thereto; design and other licensing-based compliance matters; challenges with start-up activities, including major equipment failure, or system integration, and/or operational performance; challenges related to future epidemic or pandemic health events; continued public and policymaker support for projects; environmental and geological conditions; delays or increased costs to interconnect facilities to transmission grids; and increased financing costs as a result of changes in interest rates or as a result of project delays;\n\n•legal proceedings and regulatory approvals and actions related to past, ongoing, and proposed construction projects, including state PSC or other applicable state regulatory agency approvals and FERC and NRC actions;\n\n•the ability to construct facilities in accordance with the requirements of permits and licenses, to satisfy any environmental performance standards and the requirements of tax credits and other incentives, and to integrate facilities into the Southern Company system upon completion of construction;\n\n•investment performance of the employee and retiree benefit plans and nuclear decommissioning trust funds and, with respect to retiree benefit plans, changes in actuarial assumptions and differences between the assumptions and actual values, any of the foregoing of which could cause additional funding requirements;\n\nvi\n\n    [Table of Contents](#i5f73e41dadc741329774599f12c4776d_7)                                [Index to Financial Statements](#i5f73e41dadc741329774599f12c4776d_337)\n\nCAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION\n\n(continued)\n\n•advances in technology, including the pace and extent of development of low- to no-carbon energy and battery energy storage technologies and the impact of advancing technology on data center and other large load customer demand;\n\n•performance of counterparties under ongoing renewable energy partnerships and development agreements;\n\n•state and federal rate regulations and the impact of pending and future rate cases and negotiations, including rate actions relating to ROE, equity ratios, additional generating capacity and transmission facilities, extension of retirement dates for fossil fuel plants, and fuel and other cost recovery mechanisms;\n\n•the ability to successfully operate the traditional electric operating companies', SEGCO's, and Southern Power's generation, transmission, distribution, and battery energy storage facilities, as applicable, and Southern Company Gas' natural gas distribution and storage facilities and the successful performance of necessary corporate functions;\n\n•the inherent risks involved in operating nuclear generating facilities;\n\n•the inherent risks involved in generation, transmission, and distribution of electricity and transportation and storage of natural gas, including accidents, explosions, fires, mechanical problems, discharges or releases of toxic or hazardous substances or gases, and other environmental risks;\n\n•the performance of projects undertaken by the non-utility businesses and the success of efforts to invest in and develop new opportunities;\n\n•internal restructuring or other restructuring options that may be pursued;\n\n•potential business strategies, including acquisitions or dispositions of assets or businesses, or interests therein, which cannot be assured to be completed or beneficial to Southern Company or its subsidiaries;\n\n•the ability of counterparties of Southern Company and its subsidiaries to make payments as and when due and to perform as required;\n\n•the ability to obtain new short- and long-term contracts with wholesale customers;\n\n•the direct or indirect effect on the Southern Company system's business resulting from cyber intrusion or physical attack and the threat of cyber and physical attacks;\n\n•global and U.S. economic conditions, including impacts from geopolitical conflicts, recession, inflation, changes in trade policies (including tariffs and other trade measures) of the United States and other countries, interest rate fluctuations, and financial market conditions, and the results of financing efforts;\n\n•prolonged or recurring U.S. federal government shutdowns;\n\n•access to capital markets and other financing sources;\n\n•changes in Southern Company's and any of its subsidiaries' credit ratings;\n\n•the ability of the traditional electric operating companies to obtain additional generating capacity (or sell excess generating capacity) at competitive prices;\n\n•catastrophic events such as fires, including wildfires, land movement, earthquakes, explosions, floods, high winds, tornadoes, hurricanes and other storms, solar flares, droughts, future epidemic or pandemic health events, wars, political unrest, or other similar occurrences;\n\n•the direct or indirect effects on the Southern Company system's business resulting from incidents affecting the U.S. electric grid, natural gas pipeline infrastructure, or operation of generating or storage resources;\n\n•impairments of goodwill or long-lived assets;\n\n•the effect of accounting pronouncements issued periodically by standard-setting bodies; and\n\n•other factors discussed elsewhere herein and in other reports filed by the Registrants from time to time with the SEC.\n\nThe Registrants expressly disclaim any obligation to update any forward-looking statements.\n\nvii\n\n    [Table of Contents](#i5f73e41dadc741329774599f12c4776d_7)                                [Index to Financial Statements](#i5f73e41dadc741329774599f12c4776d_337)\n\nPART I"}