Company: AILIM
Filing Date: 2025-09-16
Form Type: 424B2
Source: 0001104659-25-090464
Chunk: 8

Company: Ameren Illinois Co
Filing Date: 2025-09-16
Form: 424B2
Chunk 8
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 The bonds will be issued only in minimum denominations of $2,000 and integral multiples of $1,000 in excess thereof.

#### Maturity and Interest
The bonds will mature on March 1, 2055. We will pay interest on the bonds at a rate of 5.625% per year on March 1 and September 1 of each year (each an “interest payment date”) to the holders of record at the close of business on February 15 and August 15, whether or not a business day, prior to such interest payment date, provided that interest payable on the maturity date shall be payable to the person to whom principal shall be payable. Interest will accrue on the bonds offered by this prospectus supplement from September 1, 2025, the most recent date on which interest has been paid on the original bonds. The first interest payment date with respect to the bonds offered by this prospectus supplement is March 1, 2026.

Interest will be calculated on the basis of a 360-day year consisting of twelve 30-day months. In the event that the maturity date, any redemption date (as defined below) or any interest payment date is not a business day, the payment of principal, premium, if any, or interest payable on that date will be made on the next succeeding day that is a business day, without any interest or other payment in respect of the delay. A business day shall mean any weekday that is not a day on which banking institutions or trust companies in the Borough of Manhattan, the City and State of New York, or in the city where the corporate trust office of the mortgage trustee under the mortgage indenture is located, are obligated or authorized by law or executive order to close.

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TABLE OF CONTENTS

#### Redemption
All or a portion of the bonds may be redeemed at our option at any time or from time to time (each, a “redemption date”).

Prior to September 1, 2054 (six months prior to the maturity date of the bonds) (the “Par Call Date”), we may redeem the bonds at our option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of:

(1)

(a) the sum of the present values of the remaining scheduled payments of principal and interest thereon discounted to the redemption date (assuming