Ameren Illinois Co SEC filings AILLO
Ameren Illinois Co has 473 filings in SEC EDGAR's recent list, going back to Feb 28, 1994. Its latest annual report, Form 10-K, was filed on Feb 18, 2026 for the period ended Dec 31, 2025. The latest quarterly report (Form 10-Q) was filed on Aug 3, 2026, covering the quarter ended Jun 30, 2026. The most recent current report (Form 8-K) was filed on Aug 24, 2026 (other events). The company's fiscal year ends on December 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| 8-K |
Current report
Other events
|
Aug 24, 2026 | Aug 24, 2026 |
| 424B2 | Prospectus | Aug 18, 2026 | — |
| FWP | Free writing prospectus | Aug 17, 2026 | — |
| 424B3 | Prospectus | Aug 17, 2026 | — |
| S-3ASR | Automatic shelf registration | Aug 4, 2026 | — |
| 10-Q | Quarterly report | Aug 3, 2026 | Jun 30, 2026 |
| 8-K |
Current report
Shareholder vote results
|
May 18, 2026 | May 14, 2026 |
| 10-Q | Quarterly report | May 8, 2026 | Mar 31, 2026 |
| DEFA14C | Filing | Mar 31, 2026 | — |
| DEF 14C | Information statement | Mar 31, 2026 | May 14, 2026 |
| 10-K | Annual report | Feb 18, 2026 | Dec 31, 2025 |
| 8-K |
Current report
Material agreement, New debt
|
Dec 10, 2025 | Dec 10, 2025 |
| 10-Q | Quarterly report | Nov 6, 2025 | Sep 30, 2025 |
| 8-K |
Current report
Other events
|
Sep 26, 2025 | Sep 26, 2025 |
| 424B2 | Prospectus | Sep 16, 2025 | — |
| FWP | Free writing prospectus | Sep 15, 2025 | — |
| 424B3 | Prospectus | Sep 15, 2025 | — |
| 10-Q | Quarterly report | Aug 4, 2025 | Jun 30, 2025 |
| 8-K |
Current report
Shareholder vote results
|
May 12, 2025 | May 8, 2025 |
| 10-Q | Quarterly report | May 5, 2025 | Mar 31, 2025 |
| DEFA14C | Filing | Mar 25, 2025 | — |
| DEF 14C | Information statement | Mar 25, 2025 | May 8, 2025 |
| 8-K |
Current report
Other events
|
Mar 3, 2025 | Mar 3, 2025 |
| 424B2 | Prospectus | Feb 25, 2025 | — |
| FWP | Free writing prospectus | Feb 24, 2025 | — |
| 424B3 | Prospectus | Feb 24, 2025 | — |
| 10-K | Annual report | Feb 18, 2025 | Dec 31, 2024 |
| 8-K |
Current report
Other events
|
Dec 20, 2024 | Dec 19, 2024 |
| 10-Q | Quarterly report | Nov 7, 2024 | Sep 30, 2024 |
| 10-Q | Quarterly report | Aug 5, 2024 | Jun 30, 2024 |
| 8-K |
Current report
Other events
|
Jun 27, 2024 | Jun 27, 2024 |
| 8-K |
Current report
Other events
|
Jun 21, 2024 | Jun 20, 2024 |
| 424B2 | Prospectus | Jun 18, 2024 | — |
| FWP | Free writing prospectus | Jun 17, 2024 | — |
| 424B3 | Prospectus | Jun 17, 2024 | — |
| 8-K |
Current report
Shareholder vote results
|
May 13, 2024 | May 9, 2024 |
| 10-Q | Quarterly report | May 6, 2024 | Mar 31, 2024 |
| UPLOAD | Letter from the SEC | Apr 18, 2024 | — |
| DEFA14C | Filing | Apr 5, 2024 | — |
| DEF 14C | Information statement | Apr 5, 2024 | May 9, 2024 |
| UPLOAD | Letter from the SEC | Mar 27, 2024 | — |
| 10-K | Annual report | Feb 29, 2024 | Dec 31, 2023 |
| 8-K |
Current report
Other events
|
Dec 18, 2023 | Dec 14, 2023 |
| 8-K |
Current report
Other events
|
Nov 21, 2023 | Nov 16, 2023 |
| 10-Q | Quarterly report | Nov 9, 2023 | Sep 30, 2023 |
| S-3ASR | Automatic shelf registration | Oct 13, 2023 | — |
| 10-Q | Quarterly report | Aug 3, 2023 | Jun 30, 2023 |
| 8-K |
Current report
Other events
|
May 31, 2023 | May 31, 2023 |
| 424B2 | Prospectus | May 24, 2023 | — |
| FWP | Free writing prospectus | May 23, 2023 | — |
| 424B3 | Prospectus | May 23, 2023 | — |
| 8-K |
Current report
Shareholder vote results
|
May 12, 2023 | May 11, 2023 |
| 10-Q | Quarterly report | May 5, 2023 | Mar 31, 2023 |
| DEFA14C | Filing | Mar 28, 2023 | — |
| DEF 14C | Information statement | Mar 28, 2023 | — |
| 10-K | Annual report | Feb 22, 2023 | Dec 31, 2022 |
| 8-K |
Current report
Other events
|
Jan 23, 2023 | Jan 20, 2023 |
| 8-K |
Current report
Other events
|
Jan 9, 2023 | Jan 6, 2023 |
| 8-K |
Current report
Material agreement, New debt
|
Dec 6, 2022 | Dec 6, 2022 |
| 8-K |
Current report
Other events
|
Nov 22, 2022 | Nov 22, 2022 |
| 424B2 | Prospectus | Nov 9, 2022 | — |
| FWP | Free writing prospectus | Nov 8, 2022 | — |
| 424B3 | Prospectus | Nov 8, 2022 | — |
| 10-Q | Quarterly report | Nov 4, 2022 | Sep 30, 2022 |
| 8-K |
Current report
Other events
|
Aug 29, 2022 | Aug 29, 2022 |
| 424B2 | Prospectus | Aug 16, 2022 | — |
| FWP | Free writing prospectus | Aug 15, 2022 | — |
| 424B3 | Prospectus | Aug 15, 2022 | — |
| 10-Q | Quarterly report | Aug 8, 2022 | Jun 30, 2022 |
| 8-K |
Current report
Officer or director change, Shareholder vote results
|
May 13, 2022 | May 12, 2022 |
| 10-Q | Quarterly report | May 6, 2022 | Mar 31, 2022 |
| DEFA14C | Filing | Mar 29, 2022 | — |
| DEF 14C | Information statement | Mar 29, 2022 | May 12, 2022 |
| 10-K | Annual report | Feb 23, 2022 | Dec 31, 2021 |
| 10-Q | Quarterly report | Nov 4, 2021 | Sep 30, 2021 |
| 8-K |
Current report
Other events
|
Sep 13, 2021 | Sep 13, 2021 |
| 10-Q | Quarterly report | Aug 6, 2021 | Jun 30, 2021 |
| 8-K |
Current report
Other events
|
Jun 29, 2021 | Jun 29, 2021 |
| 424B2 | Prospectus | Jun 23, 2021 | — |
| 424B2 | Prospectus | Jun 23, 2021 | — |
| FWP | Free writing prospectus | Jun 22, 2021 | — |
| FWP | Free writing prospectus | Jun 22, 2021 | — |
| 424B3 | Prospectus | Jun 22, 2021 | — |
| 424B3 | Prospectus | Jun 22, 2021 | — |
| 10-Q | Quarterly report | May 10, 2021 | Mar 31, 2021 |
| 8-K |
Current report
Shareholder vote results
|
May 10, 2021 | May 6, 2021 |
| DEFA14C | Filing | Mar 23, 2021 | — |
| DEF 14C | Information statement | Mar 23, 2021 | May 6, 2021 |
| 10-K | Annual report | Feb 22, 2021 | Dec 31, 2020 |
| 8-K |
Current report
Other events
|
Nov 23, 2020 | Nov 23, 2020 |
| 424B2 | Prospectus | Nov 10, 2020 | — |
| FWP | Free writing prospectus | Nov 9, 2020 | — |
| 424B3 | Prospectus | Nov 9, 2020 | — |
| 10-Q | Quarterly report | Nov 5, 2020 | Sep 30, 2020 |
| S-3ASR | Automatic shelf registration | Oct 14, 2020 | — |
| 10-Q | Quarterly report | Aug 7, 2020 | Jun 30, 2020 |
| 10-Q | Quarterly report | May 11, 2020 | Mar 31, 2020 |
| 8-K |
Current report
Shareholder vote results
|
May 11, 2020 | May 7, 2020 |
| DEFA14C | Definitive additional information statement materials including rule 14(a)(12) | Mar 26, 2020 | — |
| DEF 14C | Information statement | Mar 26, 2020 | May 7, 2020 |
| 10-K | Annual report | Feb 28, 2020 | Dec 31, 2019 |
| 8-K |
Current report
Material agreement, New debt
|
Dec 11, 2019 | Dec 9, 2019 |
| 8-K |
Current report
Other events
|
Nov 26, 2019 | Nov 26, 2019 |
| 424B2 | Prospectus | Nov 19, 2019 | — |
| FWP | Free writing prospectus | Nov 18, 2019 | — |
| 424B3 | Prospectus | Nov 18, 2019 | — |
| 10-Q | Quarterly report | Nov 8, 2019 | Sep 30, 2019 |
| 10-Q | Quarterly report | Aug 2, 2019 | Jun 30, 2019 |
| 10-Q | Quarterly report | May 10, 2019 | Mar 31, 2019 |
| 8-K |
Current report
Shareholder vote results
|
May 6, 2019 | May 2, 2019 |
| DEFA14C | Definitive additional information statement materials including rule 14(a)(12) | Mar 19, 2019 | — |
| DEF 14C | Information statement | Mar 19, 2019 | May 2, 2019 |
| 10-K | Annual report | Feb 26, 2019 | Dec 31, 2018 |
| 8-K |
Current report
Material agreement, New debt
|
Dec 4, 2018 | Dec 3, 2018 |
| 8-K |
Current report
Other events
|
Nov 15, 2018 | Nov 15, 2018 |
| 424B2 | Prospectus | Nov 6, 2018 | — |
| FWP | Free writing prospectus | Nov 5, 2018 | — |
| 424B3 | Prospectus | Nov 5, 2018 | — |
| 10-Q | Quarterly report | Nov 2, 2018 | Sep 30, 2018 |
| 10-Q | Quarterly report | Aug 8, 2018 | Jun 30, 2018 |
| 8-K |
Current report
Other events
|
May 22, 2018 | May 22, 2018 |
| 424B2 | Prospectus | May 15, 2018 | — |
| FWP | Free writing prospectus | May 14, 2018 | — |
| 424B3 | Prospectus | May 14, 2018 | — |
| 10-Q | Quarterly report | May 9, 2018 | Mar 31, 2018 |
| DEFA14C | Filing | Mar 19, 2018 | — |
| DEF 14C | Information statement | Mar 19, 2018 | May 3, 2018 |
| 10-K | Annual report | Feb 28, 2018 | Dec 31, 2017 |
| S-3ASR | Automatic shelf registration | Dec 15, 2017 | — |
| 8-K |
Current report
Other events
|
Nov 28, 2017 | Nov 28, 2017 |
| 424B2 | Prospectus | Nov 17, 2017 | — |
| FWP | Free writing prospectus | Nov 16, 2017 | — |
| 424B3 | Prospectus | Nov 16, 2017 | — |
| 10-Q | Quarterly report | Nov 3, 2017 | Sep 30, 2017 |
| 10-Q | Quarterly report | Aug 4, 2017 | Jun 30, 2017 |
| 10-Q | Quarterly report | May 5, 2017 | Mar 31, 2017 |
| 8-K |
Current report
Shareholder vote results
|
May 1, 2017 | Apr 27, 2017 |
| DEFA14C | Filing | Mar 15, 2017 | — |
| DEF 14C | Information statement | Mar 15, 2017 | Apr 27, 2017 |
| 10-K | Annual report | Feb 28, 2017 | Dec 31, 2016 |
| 8-K |
Current report
Material agreement, New debt
|
Dec 8, 2016 | Dec 7, 2016 |
| 8-K |
Current report
Other events
|
Dec 6, 2016 | Dec 6, 2016 |
| 424B2 | Prospectus | Nov 30, 2016 | — |
| FWP | Free writing prospectus | Nov 29, 2016 | — |
| 424B3 | Prospectus | Nov 29, 2016 | — |
| 10-Q | Quarterly report | Nov 4, 2016 | Sep 30, 2016 |
| 10-Q | Quarterly report | Aug 5, 2016 | Jun 30, 2016 |
| UPLOAD | Letter from the SEC | Jun 20, 2016 | — |
| UPLOAD | Letter from the SEC | Jun 8, 2016 | — |
| 10-Q | Quarterly report | May 10, 2016 | Mar 31, 2016 |
| 8-K |
Current report
Shareholder vote results
|
Apr 29, 2016 | Apr 28, 2016 |
| DEFA14C | Filing | Mar 18, 2016 | — |
| DEF 14C | Information statement | Mar 18, 2016 | Apr 28, 2016 |
| 10-K | Annual report | Feb 26, 2016 | Dec 31, 2015 |
| 8-K |
Current report
Other events
|
Dec 14, 2015 | Dec 14, 2015 |
| 424B2 | Prospectus | Dec 9, 2015 | — |
| FWP | Free writing prospectus | Dec 7, 2015 | — |
| 424B3 | Prospectus | Dec 7, 2015 | — |
| 10-Q | Quarterly report | Nov 6, 2015 | Sep 30, 2015 |
| 10-Q | Quarterly report | Aug 6, 2015 | Jun 30, 2015 |
| S-3ASR | Automatic shelf registration | Jun 22, 2015 | — |
| 10-Q | Quarterly report | May 11, 2015 | Mar 31, 2015 |
| 8-K |
Current report
Shareholder vote results
|
Apr 24, 2015 | Apr 23, 2015 |
| DEF 14C | Information statement | Mar 12, 2015 | Apr 23, 2015 |
| 10-K | Annual report | Mar 2, 2015 | Dec 31, 2014 |
| 8-K |
Current report
Other events
|
Jan 23, 2015 | Jan 23, 2015 |
| 8-K |
Current report
Bylaw or fiscal year change
|
Dec 18, 2014 | Dec 12, 2014 |
| 8-K |
Current report
Material agreement, New debt
|
Dec 11, 2014 | Dec 11, 2014 |
| 8-K |
Current report
Other events
|
Dec 10, 2014 | Dec 10, 2014 |
| 424B2 | Prospectus | Dec 4, 2014 | — |
| FWP | Free writing prospectus | Dec 3, 2014 | — |
| 424B3 | Prospectus | Dec 3, 2014 | — |
| 10-Q | Quarterly report | Nov 10, 2014 | Sep 30, 2014 |
| 10-Q | Quarterly report | Aug 11, 2014 | Jun 30, 2014 |
| 8-K |
Current report
Other events
|
Jun 30, 2014 | Jun 30, 2014 |
| 424B2 | Prospectus | Jun 25, 2014 | — |
| FWP | Free writing prospectus | Jun 23, 2014 | — |
| 424B3 | Prospectus | Jun 23, 2014 | — |
| 10-Q | Quarterly report | May 12, 2014 | Mar 31, 2014 |
| 8-K |
Current report
Shareholder vote results
|
Apr 25, 2014 | Apr 24, 2014 |
| ARS | Annual report to shareholders | Mar 14, 2014 | Dec 31, 2013 |
| DEF 14C | Information statement | Mar 11, 2014 | Apr 24, 2014 |
| 10-K | Annual report | Mar 3, 2014 | Dec 31, 2013 |
| 8-K |
Current report
Other events
|
Dec 10, 2013 | Dec 10, 2013 |
| 424B2 | Prospectus | Dec 6, 2013 | — |
| FWP | Free writing prospectus | Dec 5, 2013 | — |
| 424B3 | Prospectus | Dec 5, 2013 | — |
| 10-Q | Quarterly report | Nov 8, 2013 | Sep 30, 2013 |
| 10-Q | Quarterly report | Aug 9, 2013 | Jun 30, 2013 |
| 10-Q | Quarterly report | May 10, 2013 | Mar 31, 2013 |
| 8-K |
Current report
Officer or director change, Shareholder vote results
|
Apr 23, 2013 | Apr 22, 2013 |
| ARS | Annual report to shareholders | Mar 14, 2013 | Dec 31, 2012 |
| DEF 14C | Information statement | Mar 7, 2013 | Apr 23, 2013 |
| 10-K | Annual report | Mar 1, 2013 | Dec 31, 2012 |
| 8-K |
Current report
Other events
|
Jan 25, 2013 | Jan 25, 2013 |
| 8-K |
Current report
Material agreement, Agreement ended, New debt
|
Nov 15, 2012 | Nov 14, 2012 |
| 10-Q | Quarterly report | Nov 9, 2012 | Sep 30, 2012 |
| 8-K |
Current report
Other events
|
Aug 20, 2012 | Aug 20, 2012 |
| 424B2 | Prospectus | Aug 14, 2012 | — |
| FWP | Free writing prospectus | Aug 13, 2012 | — |
Showing 200 filings, the most recent 200. Main filings leave out insider and ownership forms such as Form 4; choose a type above to see them. Each form opens on SEC.gov. Older filings are on SEC EDGAR.
New to this? Read What Are SEC Filings? 10-K, 10-Q, 8-K and Other Forms Explained.
Company profile
- Industry
- Electric & Other Services Combined (SIC 4931)
- Listed as
- AILIH (OTC), AILLI (OTC), AILLM (OTC), AILLN (OTC), AILIM (OTC), AILLO (OTC), AILIN (OTC), AILLP (OTC), AILIO (OTC), AILIP (OTC)
- Fiscal year ends
- December 31
- Incorporated in
- IL
- Headquarters
- Collinsville, IL
- SEC CIK
- 18654
- Former names
- CENTRAL ILLINOIS PUBLIC SERVICE CO (until Sep 13, 2010)
Other Electric & Other Services Combined companies
- Duke Energy CORP DUK
- Xcel Energy Inc XEL
- Exelon Corp EXC
- Consolidated Edison Inc ED
- PG&E Corp PCG
- Wec Energy Group, Inc. WEC
- Public Service Enterprise Group Inc PEG
- Ameren Corp AEE
Source: SEC EDGAR filings. This is company-reported data, not investment advice.