How does Illinois electricity billing work?

Illinois has a deregulated electricity market. Your bill may come from ComEd (northern Illinois) or Ameren Illinois (central/southern), and you may have a separate supply provider. Both supply and delivery charges need verification.

Does Utility Check support ComEd and Ameren Illinois bills?

Yes. Utility Check supports ComEd, Ameren Illinois, and alternative electricity suppliers in Illinois. We verify both supply and delivery charges, including capacity charges and transmission fees.

What is the ComEd delivery charge on my Illinois bill?

ComEd delivery charges include a customer charge, standard metering service, distribution facilities charge, and various riders and surcharges. These are separate from your electricity supply charges. Utility Check verifies both components independently.

How can I verify my Illinois electricity bill?

Upload your ComEd or Ameren Illinois bill to Utility Check. We recalculate supply charges, delivery charges, capacity charges, and all applicable riders. If you have an alternative supplier, we verify those charges against your contract terms.

Illinois Electricity Rates & Energy Plans 2026 — Compare

Illinois Electric Utilities

ComEd (Commonwealth Edison)

4 million customers

Service Cities:

Chicago Aurora Naperville Rockford Joliet

Ameren Illinois

1.2 million customers

Service Cities:

Springfield Peoria Champaign Decatur

Illinois Electricity Guide

In-depth guidance on rate plans, shopping, and bill optimization for Illinois households.

How Illinois Electricity Choice Works

Illinois deregulated electricity supply in 1997, separating the company that generates power from the company that delivers it. Today, every Illinois resident has three paths: take default service from ComEd or Ameren Illinois (rate set by twice-yearly state auctions), shop individually for an Alternative Retail Electric Supplier (ARES) at PlugInIllinois.org, or participate in your municipality's aggregation program. The Illinois Commerce Commission (ICC) regulates suppliers and runs the consumer protection framework.

Which path is cheapest changes year to year. After the 2024 default service auction, ComEd's Price to Compare jumped sharply, making ARES offers and aggregations more competitive. Always pull your current Price to Compare from your latest bill before assuming what's cheapest.

ComEd (Commonwealth Edison): Northern Illinois delivery utility — 4 million customers across Chicago and the metro area, plus Rockford and surrounding counties.
Ameren Illinois: Central and southern Illinois delivery utility — 1.2 million customers in Springfield, Peoria, Champaign-Urbana, Decatur, and rural southern Illinois.
PJM Interconnection: ComEd participates in the PJM regional grid. Capacity charges from PJM auctions flow through ComEd's Price to Compare.
MISO (Midwest ISO): Ameren Illinois participates in MISO. Different capacity dynamics than PJM — sometimes higher, sometimes lower depending on the year.

ComEd vs Ameren Illinois: A Direct Comparison

Many Illinoisans want to know how the two utilities stack up — useful especially when relocating between regions. Both are fully regulated by the Illinois Commerce Commission for delivery rates and serve as default suppliers via state auctions. The differences:

Service area: ComEd: northern third of Illinois, including Chicago. Ameren: central and southern Illinois, including Springfield and Peoria. The two don't overlap.
Default supply rate: Both set by twice-yearly auctions and change June 1 / October 1. Typical 2026 PTC range: ComEd 7-9¢/kWh; Ameren 6-8¢/kWh — Ameren slightly lower in most recent auctions.
Delivery charges: ComEd's residential delivery runs ~5¢/kWh after rider surcharges. Ameren Illinois ~4.2¢/kWh. ComEd's higher delivery reflects denser urban infrastructure and ongoing grid modernization.
Average residential bill: ComEd ~$130/month at 800 kWh. Ameren Illinois ~$120/month at 800 kWh. Both well below national average.
Time-of-use programs: ComEd offers Hourly Pricing (real-time) plus Residential Real-Time Pricing. Ameren offers Power Smart Pricing. Both can save 10-30% for households that shift usage.

Should You Switch From Default Service in Illinois?

After the 2024 default-service auction, ComEd's PTC jumped — making ARES shopping and aggregation more attractive. Here's the decision tree:

1. Pull your current Price to Compare: It's printed on your bill, usually in a 'Compare Suppliers' box. ComEd's current residential PTC is updated at ComEd.com.
2. Check if you're already in an aggregation: Look at your supply line on the bill. If the supplier name isn't ComEd or Ameren — e.g., Constellation, Direct Energy, Dynegy — you're already on a competitive supply, possibly through your city's program.
3. Compare fixed-rate ARES offers at PlugInIllinois.org: Filter for 12+ month fixed plans only. Look for offers at least 0.5¢/kWh below your PTC, with no auto-renewal at variable rates.
4. Beware of door-to-door sales: Illinois has had problems with deceptive door-to-door supplier sales. The ICC requires written disclosures, but many customers report being switched without clear consent. Always verify offers in writing before signing.
5. Re-shop annually: Even on a fixed-rate plan, set a calendar reminder for 30 days before contract end. Auto-renewal at variable rates is the most common way customers lose savings.

ComEd Hourly Pricing and Time-of-Use Programs

ComEd offers two real-time pricing options that can dramatically lower bills for households who can shift usage. Both require Smart Meters (most ComEd customers already have them) and active management:

Hourly Pricing: Charges the actual wholesale market price each hour, plus a small fixed adder. Best for: EV owners charging overnight, households with pool pumps or thermal storage, anyone willing to shift dishwasher/laundry to off-peak hours.
Residential Real-Time Pricing (RRTP): A variant offering more predictability via day-ahead price signals. Lower risk than Hourly Pricing during summer peaks.
Smart Thermostat Rebate: ComEd customers on hourly pricing get rebates for compatible smart thermostats that auto-adjust to price signals. See our smart thermostats guide.
Off-peak EV Charging: Hourly pricing typically saves EV owners 30-50% on charging costs vs flat-rate plans. Combine with a Level 2 charger and timer for biggest gains. See our Level 2 EV chargers guide.

Common Illinois Bill Errors and Hidden Charges

Illinois bills include many ICC-approved riders that aren't always self-explanatory. The most common audit issues:

Misclassified rate plan: Customers who recently moved or switched accounts can end up on the wrong default rate (residential vs. small commercial). The customer charge alone differs by $5-$15/month.
Energy Efficiency Programs (EEP) rider: All Illinois customers fund efficiency programs through a small per-kWh rider. The rider amount changes annually — verify on the line item.
Estimated reads after meter swaps: When ComEd or Ameren swap meters (smart meter rollout, replacement), the next bill is often estimated. Estimates can run high — check the actual read on your next bill.
Aggregation lapse: Municipal aggregations have term limits. When the term ends and the city doesn't renew, you auto-flip to default service — sometimes at a higher rate than the prior aggregation. Check your bill's supplier name annually.
Auto-renewal of ARES contracts at variable rates: The single biggest source of overpayment in Illinois — fixed-rate ARES contracts that auto-renew to month-to-month variable rates 30-60% higher. Set calendar reminders.

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