SEC Form 4
FORM 4UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
  
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
Kim Matthew M.

(Last)(First)(Middle)
30 IVAN ALLEN JR. BLVD., NW

(Street)
ATLANTA GEORGIA 30308

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
SOUTHERN CO [ SO ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director10% Owner
XOfficer (give title below)Other (specify below)
Comptroller
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
04/01/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeVAmount(A) or (D)Price
Southern Company Common Stock04/01/2026M82(1)A$06,970D
Southern Company Common Stock04/01/2026F82(2)D$96.946,888D
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Southern Co Restricted Stock Units$004/01/2026M13(3) (3) (3)Southern Company Common Stock13$0305D
Southern Co Restricted Stock Units$004/01/2026M23(4) (4) (4)Southern Company Common Stock23$0539D
Performance Restricted Stock Units$004/01/2026M42(5) (5) (5)Southern Company Common Stock42$0975D
Explanation of Responses:
1. Represents shares delivered to the Company to cover FICA withholding obligations due because Reporting Person is retirement eligible pursuant to his applicable stock grant documents. Includes 4 accrued dividend equivalent units.
2. Represents shares delivered to the Company to cover FICA withholding obligations due because Reporting Person is retirement eligible pursuant to his applicable stock grant documents.
3. Represents restricted stock units granted on January 31, 2024, payable in Southern Company common stock and will continue to vest on the third anniversary of the grant date. Additional units will be acquired with deemed dividends. Shares will be withheld upon vesting to satisfy income tax requirements.
4. Represents restricted stock units granted on February 5, 2025, payable in Southern Company common stock and will continue to vest on the remaining second and third anniversary of the grant date. Additional units will be acquired with deemed dividends. Shares will be withheld upon vesting to satisfy income tax requirements.
5. Represents restricted stock units granted on February 11, 2026, payable in Southern Company common stock and vest every year on the first, second and third anniversary of the grant date. Additional units will be acquired with deemed dividends. Shares will be withheld upon vesting to satisfy income tax requirements.
/s/ Brittney Anderson, Attorney-in-Fact for Matthew M. Kim04/02/2026
** Signature of Reporting PersonDate
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)