Switching electricity in Illinois — ComEd, Ameren, Plug In Illinois

Illinois utility territories

ComEd: Chicago metro and northern Illinois. About 4 million customers. Sits inside PJM. Average residential SSO rate for early 2026: ~6.8¢/kWh.

Ameren Illinois: central and southern Illinois. About 1.2 million customers. Sits inside MISO. Average residential rate for early 2026: ~7.2¢/kWh.

MidAmerican Energy: northwestern corner (Quad Cities). About 100,000 IL customers. Different rate structure.

How to switch in Illinois

Step 1: visit pluginillinois.org. Enter ZIP; the portal identifies your utility. Step 2: review the ARES list. Each is licensed by the ICC; the portal lists rate, term, contract type, customer charge.

Step 3: pick a supplier and enroll. The ARES sends an EDI 814 to your utility within 24 hours. Switch effective at next utility meter read (30-45 days).

Step 4: the 10-business-day rescission. Cancel any contract within 10 business days without penalty. The cooling-off-period-energy-supplier-rights guide walks the rule across all states.

Illinois consumer protections (the strongest in the country)

Illinois has the longest rescission window in the country at 10 business days. After signing any ARES contract you can cancel within 10 business days without penalty. The cooling-off-period-energy-supplier-rights guide walks the rule across all states; Illinois sits at the protective end.

Right to terminate without an early-termination fee after January 1, 2020 — Illinois law eliminated ETFs for residential and small commercial supplier contracts. You can switch suppliers at any time, no fee. Some contracts signed before 2020 still carry legacy ETFs; check your specific terms.

ARES license verification: every IL ARES holds an ICC license number visible on the Plug In Illinois portal. Always verify the license before signing — the supplier-license-how-to-verify guide covers the verification process. Door-to-door sales are tightly regulated; reps must show ICC ID badges and provide written disclosures.

Slamming protection: ICC enforces strict anti-slamming rules. If your account is switched without authorization, the ICC consumer division opens an investigation within 7 days and can fine the offending ARES. Document everything if it happens.

ComEd customers and the PJM market context

ComEd sits inside the PJM regional grid, which means ComEd customers are exposed to PJM capacity-auction outcomes that flow through to delivery charges. The 2025-2026 PJM capacity auction cleared at the highest prices in a decade, which is starting to show up on ComEd delivery lines as 8 to 15 percent rate increases. The capacity-market-pjm-ercot-explained guide walks the mechanics.

ComEd default supply (the "PIPP" or Purchased Electricity rate) resets every June and October based on a wholesale procurement auction. Customers on default service see twice-yearly rate adjustments. Customers on a fixed-rate ARES contract are insulated for the term they signed (typically 12 to 24 months).

Hourly Pricing program: ComEd offers an opt-in real-time pricing rate where customers pay the wholesale hourly market price. This is risky for households without active load-shifting capability — wholesale prices can spike from $0.03 to over $5 per kWh during scarcity events. Not recommended for default consumers; useful for sophisticated customers with battery storage or aggressive demand response.

Ameren Illinois and the MISO market context

Ameren Illinois sits inside the MISO regional grid, which has different capacity dynamics than PJM. Ameren default supply rates have historically run lower than ComEd because MISO has more excess generation capacity. As of early 2026, Ameren residential default sits around 7.2 cents per kWh; ARES offers typically run 5.8 to 6.8 cents per kWh fixed.

Ameren also operates a Power Smart Pricing program (similar to ComEd Hourly Pricing) for households interested in real-time wholesale pricing. Same warnings apply — useful for sophisticated customers, dangerous for typical households without load-shifting capability.

For multi-fuel customers (electric + gas via Ameren Illinois, which serves both), each commodity is shopped separately. Bundling discounts from ARES are usually small. Compare each contract on its own per-unit rate before considering a bundle.