Utility overview
- Legal name
- Ameren Illinois Company d/b/a Ameren Illinois
- Parent organization
- Ameren Corporation
- Ownership type
- Investor-Owned
- Utility class
- Major Regulated
Official website and contact
- Official website: Visit official website (opens in a new tab)
- Customer service: 1-800-755-5000
- Gas emergency: Not listed
- Email: Not listed
- Address: Not listed
Published state services
Illinois — IL
Service area: Central and southern Illinois; 816,000 natural gas customers (company service-territory page).
Rate jurisdiction: Illinois Commerce Commission
Customer classes: Commercial, Residential
Last confirmed: Aug 22, 2026
- State customer URL: Open link (opens in a new tab)
- Tariff or territory source: Open link (opens in a new tab)
Utility identity sources
- Ameren Illinois Service Territory (opens in a new tab)
Official Utility Website · Ameren
- Rate GDS-1 – Residential Gas Delivery Service (opens in a new tab)
Tariff · Ameren Illinois, Ill. C.C. No. 2
- Rate GDS-2 – Small General Gas Delivery Service (opens in a new tab)
Tariff · Ameren Illinois
State-service sources
Illinois — IL
- Natural Gas authority (opens in a new tab)
State Regulator Inventory · Illinois Commerce Commission
Verified utility identity
Verified means GCC confirmed utility identity, retail gas-distribution status, and state-service evidence against authoritative sources.
Confirmation status
- Last confirmed
- Aug 22, 2026
- Reconfirmation status
- Current
Directory-information notice
GCC provides directory information only. Listings are not legal advice, regulatory advice, endorsements, or guarantees of utility service eligibility.
Service-area summaries are high-level and do not guarantee service at a specific address. Contact the listed utility directly for address-level eligibility.