Company: SOJE
Filing Date: 2025-11-04
Form Type: 424B2
Source: 0000092122-25-000092
Chunk: 198

Company: SOUTHERN CO
Filing Date: 2025-11-04
Form: 424B2
Chunk 198
---
 they may receive customary compensation.

The Company’s common stock is listed on the New York Stock Exchange. Each series of Senior Notes, Junior Subordinated Notes, Stock Purchase Contracts or Stock Purchase Units will be a new issue of securities and will have no established trading market. Any underwriters to whom Senior Notes, Junior Subordinated Notes, Stock Purchase Contracts or Stock Purchase Units are sold for public offering and sale may make a market in such Senior Notes, Junior Subordinated Notes, Stock Purchase Contracts or Stock Purchase Units, but such underwriters will not be obligated to do so and may discontinue any market making at any time without notice. The Senior Notes, Junior Subordinated Notes, Stock Purchase Contracts or Stock Purchase Units may or may not be listed on a national securities exchange.

### LEGAL MATTERS
The validity of the Common Stock, the Senior Notes, the Junior Subordinated Notes, the Stock Purchase Contracts and the Stock Purchase Units and certain matters relating to such securities will be passed upon on behalf of the Company by Troutman Pepper Hamilton Sanders LLP, Atlanta, Georgia. Certain legal matters will be passed upon for the underwriters by Hunton Andrews Kurth LLP, New York, New York. From time to time, Hunton Andrews Kurth LLP acts as counsel to affiliates of the Company for some matters.

### EXPERTS
The consolidated financial statements, and the related financial statement schedule, incorporated in this Prospectus by reference from the Form 10-K, and the effectiveness of the Company’s internal control over financial reporting have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their reports, which are incorporated herein by reference. Such consolidated financial statements and financial statement schedule have been so incorporated in reliance upon the reports of such firm given upon their authority as experts in accounting and auditing.

<div align='center'>11</div>

#### 35,000,000 2025 Series A Equity Units
<div align='center'>(Initially Consisting of 35,000,000 2025 Series A Corporate Units)</div>

### PROSPECTUS SUPPLEMENT
<div align='center'>November 3, 2025</div>

<div align='center'>Joint Book-Running Managers</div>

| BofA Securities |     |      |                         |     | J.P. Morgan         |                |     |            |     | Mizuho                 |
| Citigroup       |     |      | Goldman Sachs & Co. LLC |     |                     | Morgan Stanley |