# EDGAR Filing Document

**Accession Number:** 0001160661
**File Stem:** 0001160661-26-000004
**Filing Date:** 2026-6
**Character Count:** 4814
**Document Hash:** 878ae759e18cef36c2dc80c14972e994
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001160661-26-000004.hdr.sgml**: 20260601

**ACCESSION NUMBER**: 0001160661-26-000004

**CONFORMED SUBMISSION TYPE**: FWP

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260601

**DATE AS OF CHANGE**: 20260601

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** SOUTHERN POWER CO
- **CENTRAL INDEX KEY:** 0001160661
- **STANDARD INDUSTRIAL CLASSIFICATION:** ELECTRIC SERVICES [4911]
- **ORGANIZATION NAME:** 01 Energy & Transportation
- **EIN:** 582598670

**FILING VALUES:**
- **FORM TYPE:** FWP
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 333-289172
- **FILM NUMBER:** 261050453

**BUSINESS ADDRESS:**
- **STREET 1:** 30 IVAN ALLEN JR. BLVD
- **CITY:** ATLANTA
- **STATE:** GA
- **ZIP:** 30308
- **BUSINESS PHONE:** 4045065000

**MAIL ADDRESS:**
- **STREET 1:** 30 IVAN ALLEN JR. BLVD
- **CITY:** ATLANTA
- **STATE:** GA
- **ZIP:** 30308
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** SOUTHERN POWER CO
- **CENTRAL INDEX KEY:** 0001160661
- **STANDARD INDUSTRIAL CLASSIFICATION:** ELECTRIC SERVICES [4911]
- **ORGANIZATION NAME:** 01 Energy & Transportation
- **EIN:** 582598670

**FILING VALUES:**
- **FORM TYPE:** FWP

**BUSINESS ADDRESS:**
- **STREET 1:** 30 IVAN ALLEN JR. BLVD
- **CITY:** ATLANTA
- **STATE:** GA
- **ZIP:** 30308
- **BUSINESS PHONE:** 4045065000

**MAIL ADDRESS:**
- **STREET 1:** 30 IVAN ALLEN JR. BLVD
- **CITY:** ATLANTA
- **STATE:** GA
- **ZIP:** 30308

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| **Filed Pursuant to Rule 433** |
| **Registration No. 333-289172** |
| **June 1, 2026** |

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| **PRICING TERM SHEET** | **PRICING TERM SHEET** |
| **(To Preliminary Prospectus Supplement dated June 1, 2026)** | **(To Preliminary Prospectus Supplement dated June 1, 2026)** |
| Issuer: | Southern Power Company |
| Security: | Series 2026A 4.80% Senior Notes due June 15, 2031 |
| Expected Ratings:\* | Baa1 (Stable)/BBB+ (Stable)/BBB+ (Stable) (Moody's/Standard & Poor's/Fitch) |
| Principal Amount: | $600000000 |
| Initial Public Offering Price: | 99.972% |
| Maturity Date: | June 15, 2031 |
| Treasury Benchmark: | 4.125% due May 31, 2031 |
| Benchmark Treasury Yield: | 4.186% |
| Spread to Treasury: | +62 basis points |
| Re-offer Yield: | 4.806% |
| Optional Redemption: |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Make-Whole Call: | Prior to April 15, 2031 at T+10 basis points |
| &nbsp;&nbsp;&nbsp;&nbsp;Par Call: | On or after April 15, 2031 at 100% |
| Call for Tax Credit Event: | In whole, but not in part, at 101% of the principal amount, plus any accrued and unpaid interest thereon (notice may be issued no later than December 31, 2026, for a redemption not less than 15 nor more than 60 days after such notice) |
| Coupon: | 4.80% |
| Interest Payment Dates: | June 15 and December 15 of each year, beginning December 15, 2026 |
| Format: | SEC Registered |
| Denominations: | $2,000 and integral multiples of $1,000 in excess thereof |
| CUSIP/ISIN: | 843646 AZ3/US843646AZ36 |
| Trade Date: | June 1, 2026 |
| Expected Settlement Date: | June 4, 2026 (T+3) |
| Joint Book-Running Managers: | BMO Capital Markets Corp.<br>BofA Securities, Inc.<br>PNC Capital Markets LLC<br>SMBC Nikko Securities America, Inc. |
| Co-Managers: | Loop Capital Markets LLC<br>BBVA Securities Inc.<br>TD Securities (USA) LLC<br>FHN Financial Securities Corp.<br>Hancock Whitney Investment Services, Inc.<br>AmeriVet Securities, Inc.<br>Cabrera Capital Markets LLC<br>Independence Point Securities LLC<br>Security Capital Brokerage, Inc. |

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| \* Note: A securities rating is not a recommendation to buy, sell or hold securities and may be subject to revision or withdrawal at any time. |
| The term "Tax Credit Event" has the meaning ascribed to it in the issuer's Preliminary Prospectus Supplement dated June 1, 2026. |
| The issuer has filed a registration statement (including a prospectus) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents the issuer has filed with the SEC for more complete information about the issuer and this offering. You may get these documents for free by visiting EDGAR on the SEC Web site at www.sec.gov. Alternatively, the issuer, any underwriter or any dealer participating in this offering will arrange to send you the prospectus if you request it by calling Southern Power Company collect at 1-404-506-0727, BMO Capital Markets Corp. toll free at 1-888-200-0266, BofA Securities, Inc. toll free at 1-800-294-1322 or by email at dg.prospectus_requests@bofa.com, PNC Capital Markets LLC toll free at 1-855-881-0697 or SMBC Nikko Securities America, Inc. toll free at 1-888-868-6856 or by email at prospectus@smbcnikko-si.com. |

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