The ICC lists Nicor Gas among utilities with residential and small-commercial gas-choice programs. Verify the actual service class, current program terms and supplier registration. Utility delivery continues and its fixed and usage charges belong in the budget.
Confirm the account before selecting a product
Use a current bill for the service premises. Identify the delivery utility, commodity, customer class, account holder and applicable tariff. A city name, supplier logo or prior tenant’s information is not a substitute. Check who can authorize a supply change and whether existing contractual obligations must be resolved. Keep account numbers out of a general inquiry.
Keep units consistent
A therm measures heat energy; a gas bill may also display a volume measurement and a conversion factor. Quote units must match the billed usage before calculating cost. The commodity price, monthly supplier fee, utility distribution charge and tax are separate components. If a quote uses a wholesale reference or a different energy unit, ask for an explicit conversion and the full delivered pricing formula rather than comparing the raw numbers.
Distinguish choice from transportation
The ICC describes small-customer choice programs in Nicor Gas, Peoples Gas and North Shore Gas territories. Ameren publishes a separate business gas transportation pathway. Transportation can involve supplier nominations, balancing, storage or other obligations beyond a simple commodity rate. Eligibility and timing follow the utility and account. Do not infer gas service options from your electric utility or treat every Illinois business as enrolled in the same program.
Stress-test winter exposure
Build a monthly usage profile rather than multiplying a mild month’s bill by twelve. Compare a base month, higher consumption at the same price, and higher consumption with a higher variable price. Fixed supply can reduce commodity price uncertainty while leaving weather-driven consumption uncertain. Document whether each price includes basis, transportation-related tasks and fees; missing inclusions can be larger than the difference between two advertised commodity prices.
An example gas budget
Illustrative inputs: 1,200 therms at $0.60 per therm and a $20 monthly supplier fee model to $740 for supply. If consumption rises 25%, the same price and fee model to $920. If only the commodity price rises 25%, the result is also $920 for this example, but both changes together would be $1,145. These are arithmetic scenarios, not quotes or predictions. Utility distribution charges and taxes still need a separate budget.
Use Customer Select information for the actual class
Nicor's Customer Select resource is a useful starting point for supplier and program checks. Record the account's class, current supply arrangement and any existing agreement before comparing a new offer. Compare billed therms and supplier fees; the utility delivery portion remains a separate budget component.
Verification before acting
For an indexed proposal, request the exact index, pricing month and adder. For a fixed proposal, identify which components remain adjustable. Confirm enrollment timing and treatment of a missed start. The first relevant invoice should be reconciled to service dates and quantities rather than compared only with the prior month's total.
Decide what a review can actually change
A useful review states the problem first: an unclear charge, a supply renewal, a demand peak, seasonal gas exposure or responsibility across multiple meters. Separate opportunities under the account’s actual rules. Do not treat a supply agreement as backup power or a calculator as utility approval. Ask for written explanations when a component or eligibility condition is unclear.
Sources & further checks
Primary references checked for this guide on October 15, 2026. Follow the source for current tariffs, eligibility and program terms; rates here are not live offers.