0001193125-25-293344 Sample Contracts

Spire Inc. $450,000,000 6.250% Series A Junior Subordinated Notes due 2056 $450,000,000 6.450% Series B Junior Subordinated Notes due 2056 UNDERWRITING AGREEMENT
Underwriting Agreement • November 24th, 2025 • Spire Inc • Natural gas distribution • New York

The Securities are to be issued pursuant to the Junior Subordinated Indenture (the “Base Indenture”), as amended or supplemented by the First Supplemental Indenture thereto (the “Supplemental Indenture”), each dated as of the Closing Date between the Company and Regions Bank, as trustee (the “Trustee”). The Base Indenture, as so amended or supplemented, is referred to herein as the “Indenture.”

FIRST SUPPLEMENTAL INDENTURE BETWEEN SPIRE INC. AND REGIONS BANK, AS TRUSTEE DATED AS OF NOVEMBER 24, 2025 6.250% SERIES A JUNIOR SUBORDINATED NOTES DUE 2056 6.450% SERIES B JUNIOR SUBORDINATED NOTES DUE 2056
Supplemental Indenture • November 24th, 2025 • Spire Inc • Natural gas distribution • New York

THIS FIRST SUPPLEMENTAL INDENTURE, dated as of November 24, 2025 (this “First Supplemental Indenture”), is between Spire Inc., a Missouri corporation, having its principal office at 700 Market Street, St. Louis, Missouri 63101 (the “Company”), and Regions Bank, a banking corporation, as trustee under the Base Indenture (as defined below), having a corporate trust office at 8182 Maryland Avenue, 12th Floor, Clayton, Missouri 63105, Attention: Corporate Trust Services (herein called the “Trustee”).