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How to check commercial gas supplier choice in Illinois

Start with the gas service company, not the state’s reputation for deregulation. The table below connects each represented utility to its actual account classification and enrollment question.

Reviewed October 16, 2026

By Commercial Gas Rates editorial team · Educational guidance; verify account-level terms.

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Illinois: Prove the available service before requesting a price

Start with EIA: natural gas customer choice and eligibility. The table below links this decision to the represented gas companies in Illinois. It does not establish service or supplier availability for every account.

Authorization is only one gate

A regulator’s supplier approval and a utility’s accepted supplier or agent are different checks. A licensed company may decline a particular volume, credit profile or service class. Obtain written acceptance for the listed accounts.

Return service needs its own answer

Ask what happens if a supply agreement ends or an agent stops performing. Confirm the utility’s return conditions and start date; a supplier cancellation does not itself establish an accepted replacement enrollment.

Illinois utility application

Gas service companyClassification and accepted enrollmentPrimary reference
Nicor GasSupplier registration, cancellation terms and return-to-utility conditionsOfficial program / tariff
Ameren IllinoisWritten transportation qualification before treating a marketer proposal as executableOfficial program / tariff
Peoples GasSupplier registration, cancellation terms and return-to-utility conditionsOfficial program / tariff
North Shore GasSupplier registration, cancellation terms and return-to-utility conditionsOfficial program / tariff
MidAmerican EnergyState tariff, supplier/transport availability and the accepted service agreementOfficial program / tariff

Nicor Gas: the program detail behind this decision

The ICC identifies Nicor Gas, Peoples Gas and North Shore Gas for residential and small-commercial Gas Choice. An Alternative Gas Supplier sells supply while the delivery utility remains. The ICC’s utility list does not establish that every supplier accepts every commercial class or offers a suitable contract. Program Illinois.

Apply the evidence to an account file

Resolve The named delivery company and its eligible small-commercial service class first. The utility or accepted agent must confirm Supplier registration, cancellation terms and return-to-utility conditions. Retain that answer alongside the named accounts before requesting bids.

An enrollment file that can be handed to another reviewer

Build six fields before seeking a signature: legal gas company; commercial rate code; eligible service arrangement; regulator authorization where required; utility-active supplier or agent; and accepted account/start-date confirmation. Attach the source date and the person who answered each unresolved question. A directory entry belongs in the authorization field, not the accepted-enrollment field. If an account remains on bundled utility service, document that result instead of forcing the review to select a supplier.

Turn the review into a calculation

Plan notice and enrollment milestones. The planner uses your calendar-day inputs and does not send notices or confirm a utility enrollment date.

Read the Illinois utility guide for the wider service-company distinctions. Convert billed gas units using the bill’s heat-content factor when moving from volume to energy.

Sources and review notes

Reviewed October 16, 2026. Program information can change. Confirm the effective utility tariff, supplier availability and written offer before proceeding. Examples and planning tools are educational; they are not executable quotes or verified customer results.

A practical next step

Put the full contract in view.

Ask about your utility, supply terms or renewal. Keep account numbers and documents out of the initial inquiry.

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