SOUTHERN CO

(L)SEGMENT AND RELATED INFORMATION

See Note 16 to the financial statements in Item 8 of the Form 10-K for additional information.

The primary businesses of the Southern Company system are electricity sales by the traditional electric operating companies and Southern Power and the distribution of natural gas by Southern Company Gas. The traditional electric operating companies are vertically integrated utilities providing electric service inthree Southeastern states. Southern Power develops, constructs, acquires, owns, operates, and manages power generation assets, including renewable energy and battery energy storage projects, and sells electricity at market-based rates in the wholesale market. Southern Company Gas distributes natural gas through its natural gas distribution utilities and is involved in several other complementary businesses including gas pipeline investments and gas marketing services.

Southern Company's reportable business segments are the sale of electricity by the traditional electric operating companies, the sale of electricity in the competitive wholesale market by Southern Power, and the sale of natural gas and other complementary products and services by Southern Company Gas. While the traditional electric operating companies represent three separate operating segments, they are vertically integrated utilities providing electric service to retail customers, as well as wholesale customers, in the Southeast and have been aggregated into one reportable segment. Revenues from sales by Southern Power to the traditional electric operating companies were $116 million and $92 million for the three months ended March 31, 2025 and 2024, respectively. Revenues from sales of natural gas from Southern Company Gas to the traditional electric operating companies and Southern Power were immaterial for both periods presented. The "All Other" column includes the Southern Company parent entity, which does not allocate operating expenses to business segments. Also, this category includes segments below the quantitative threshold for separate disclosure. These segments include providing distributed energy and resilience solutions and deploying microgrids for commercial, industrial, governmental, and utility customers, as well as investments in telecommunications. All other inter-segment revenues are not material.

Southern Company's CODM utilizes segment net income, including variances to budget and forecasts, to assess performance and is not provided with segment expense information. To achieve the consolidated net income goal, Southern Company's CODM sets net income expectations for each operating segment, which is expected to monitor its expenses in order to achieve its assigned net income target. Therefore, Southern Company has no reportable significant segment expenses.

Financial data for business segments for the three months ended March 31, 2025 and 2024 was as follows:

(a)Primarily consists of fuel, purchased power, cost of natural gas, cost of other sales, other operations and maintenance, taxes other than income taxes, AFUDC equity, non-service cost-related retirement benefits income, and net income (loss) attributable to noncontrolling interests.

(b)For Southern Power, includes pre-tax accelerated depreciation of $27 million ($20 million after tax) related to the repowering of the Kay Wind facility. See Note (K) under "Southern Power – Wind Repowering Projects" herein and Note 15 to the financial statements under "Southern Power – Development Projects" in Item 8 of the Form 10-K for additional information.

(c)Attributable to Southern Company.

Traditional Electric Operating Companies

Each of the traditional electric operating companies' single reportable business segment is the sale of electricity.

Alabama Power and Georgia Power have identified utility operations and maintenance expenses as significant segment expenses provided to their CODMs. Utility operations and maintenance expenses is calculated as other operations and maintenance, as reflected on the statements of income, less expenses from unregulated products and services, losses (gains) on asset dispositions, impairment charges, and amortization of cloud software. Alabama Power's utility operations and maintenance expenses are disaggregated into expenses related to Rate RSE and Rate CNP Compliance, which are not applicable to Georgia Power. See Note 2 to the financial statements under "Alabama Power" in Item 8 of the Form 10-K for additional information.

Financial data for Alabama Power's and Georgia Power's significant segment expenses and other segment information for the three months ended March 31, 2025 and 2024 was as follows:

(*)Primarily consists of fuel, purchased power, expenses from unregulated products and services, losses (gains) on asset dispositions, impairment charges, amortization of cloud software, taxes other than income taxes, AFUDC equity, and non-service cost-related retirement benefits income. Also includes earnings from equity method investments, which were immaterial for both periods presented.

Mississippi Power's CODM utilizes segment expense information in the form of variances to budget to assess performance; therefore, Mississippi Power has no reportable significant segment expenses. Mississippi Power's segment information for revenues, depreciation and amortization, interest expense, and income taxes is reflected on its statements of income. Mississippi Power's earnings from equity method investments are included in other income (expense), net on its statements of income and were immaterial for all periods presented. Other segment items primarily consist of fuel and purchased power, other operations and maintenance, taxes other than income taxes, and non-service cost-related retirement benefits income and totaled $277 million and $216 million for the three months ended March 31, 2025 and 2024.

Southern Power's single reportable business segment is the sale of electricity in the competitive wholesale market. Southern Power's CODM utilizes segment expense information in the form of variances to budget to assess performance; therefore, Southern Power has no reportable significant segment expenses. Southern Power's segment information for revenues, depreciation and amortization, interest expense, and income taxes (benefit) is reflected on its consolidated statements of income. Southern Power had no earnings from equity method investments for any period presented. Other segment items primarily consist of fuel, purchased power, other operations and maintenance, taxes other than income taxes, interest income, and net income (loss) attributable to noncontrolling interests and totaled $303 million and $244 million for three months ended March 31, 2025 and 2024.

For the three months ended March 31, 2025, depreciation and amortization includes pre-tax accelerated depreciation of $27 million ($20 million after tax) related to the repowering of the Kay Wind facility. See Note (K) under "Southern Power – Wind Repowering Projects" herein and Note 15 to the financial statements under "Southern Power – Development Projects" in Item 8 of the Form 10-K for additional information.

Southern Company Gas manages its business through three reportable segments – gas distribution operations, gas pipeline investments, and gas marketing services. The non-reportable segments are combined and presented as all other.

The gas distribution operations segment is the largest component of Southern Company Gas' business and includes natural gas local distribution utilities that construct, manage, and maintain intrastate natural gas pipelines and gas distribution facilities infour states.

The gas pipeline investments segment consists of joint ventures in natural gas pipeline investments including a 50% interest in SNG and a 50% joint ownership interest in the Dalton Pipeline. These natural gas pipelines enable the provision of diverse sources of natural gas supplies to the customers of Southern Company Gas. See Note 7 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information.

The gas marketing services segment provides natural gas marketing to end-use customers primarily in Georgia and Illinois through SouthStar.

The "All Other" column includes segments and subsidiaries that fall below the quantitative threshold for separate disclosure, including storage and fuels operations.

Southern Company Gas' CODM utilizes segment expense information in the form of variances to budget to assess performance; therefore, Southern Company Gas has no reportable significant segment expenses.

Financial data for business segments for the three months ended March 31, 2025 and 2024 was as follows:

(*)Primarily consists of cost of natural gas, other operations and maintenance, taxes other than income taxes, AFUDC equity, and non-service cost-related retirement benefits income.