Financing (Tables)

9 Months Ended

Sep. 30, 2025

Debt Disclosure [Abstract]

Schedule of Credit Arrangements

At September 30, 2025, committed credit arrangements with banks were as follows:

	Expires
Company	2026		2027		2029		2030		Total		Unused		Expires within One Year
	(in millions)
Southern Company parent(a)	$	—	$	500	$	—	$	2,500	$	3,000	$	2,999	$	—
Alabama Power(b)	15		—		650		700		1,365		1,365		—
Georgia Power(c)	—		—		—		2,050		2,050		2,042		—
Mississippi Power(a)	—		125		—		150		275		275		—
Southern Power(a)(d)	—		—		—		600		600		600		—
Southern Company Gas(e)	—		—		—		1,600		1,600		1,598		—
SEGCO	30		—		—		—		30		30		30
Southern Company	$	45	$	625	$	650	$	7,600	$	8,920	$	8,909	$	30

(a)Arrangement expiring in 2030 represents a $3.25 billion combined arrangement for Southern Company, Mississippi Power, and Southern Power allowing for flexible sublimits. Pursuant to the combined facility, the allocations among Southern Company, Southern Power, and Mississippi Power may be adjusted.

(b)Includes $15 million expiring in 2026 at Alabama Property Company, a wholly-owned subsidiary of Alabama Power, of which $15 million was unused at September 30, 2025. Alabama Power is not party to this arrangement.

(c)Georgia Power had $26 million of letters of credit outstanding under an uncommitted letter of credit facility at September 30, 2025.

(d)Does not include Southern Power Company's $75 million and $100 million continuing letter of credit facilities for standby letters of credit, expiring in 2027 and 2028, respectively, of which $17 million and $4 million, respectively, was unused at September 30, 2025. In addition, Southern Power Company had $23 million of letters of credit outstanding under an uncommitted letter of credit facility at September 30, 2025. Southern Power's subsidiaries are not parties to its bank credit arrangements or letter of credit facilities.

(e)Southern Company Gas, as the parent entity, guarantees the obligations of Southern Company Gas Capital, which is the borrower of $800 million of the credit arrangement expiring in 2030. Southern Company Gas' committed credit arrangement expiring in 2030 also includes $800 million for which Nicor Gas is the borrower and which is restricted for working capital needs of Nicor Gas. Pursuant to the multi-year credit arrangement expiring in 2030, the allocations between Southern Company Gas Capital and Nicor Gas may be adjusted.

Schedule of Forward Contracts Indexed to Issuer's Equity

The table below reflects shares of Southern Company common stock sold under separate forward sale contracts with forward purchasers during the nine months ended September 30, 2025.

Shares Sold	Initial Forward Price per Share	To be Settled On or Before
292,694(a)	$83.3293	December 31, 2025
563,386	$87.9027	December 31, 2025
1,000,000	$88.7502	June 30, 2026
1,000,000	$88.7739	June 30, 2026
1,000,000	$91.2856	June 30, 2026
1,000,000	$89.1444	June 30, 2026
1,000,000	$88.8490	June 30, 2026
1,000,000	$88.8903	June 30, 2026
1,000,000	$90.9196	June 30, 2026
1,255,000	$91.0566	June 30, 2026
1,324,942	$88.7048	December 31, 2026
2,277,113	$88.3227	December 31, 2026
3,130,641	$88.2823	December 31, 2026
3,255,866	$89.4692	December 31, 2026
3,850,000	$90.6617	December 31, 2026
2,470,306	$94.5394	June 30, 2027
2,314,487	$92.7805	June 30, 2027
1,590,200	$93.4524	June 30, 2027
4,000,000	$90.8141	June 30, 2027
2,346,903	$91.1610	June 30, 2027
2,876,034	$92.2437	June 30, 2027
2,642,878(b)	$93.4521(b)	June 30, 2027

(a)The total number of shares sold under this forward sale contract is 436,614, of which the first 143,920 shares were sold in December 2024.

(b)The total number of shares sold under this forward sale contract is 3,015,668, of which the remaining 372,790 shares were sold subsequent to September 30, 2025. The initial forward price was determined after the completion of sales by the forward seller in October 2025.

Schedule of Shares Used to Compute Diluted Earnings Per Share

Shares used to compute diluted EPS were as follows:

	Three Months Ended September 30,		Nine Months Ended September 30,
	2025	2024	2025	2024
	(in millions)
As reported shares	1,102	1,097	1,101	1,096
Effect of stock-based compensation	6	6	6	6
Effect of convertible senior notes	1	—	1	—
Effect of forward sale contracts	1	—	—	—
Diluted shares	1,110	1,103	1,108	1,102