How Commercial Natural Gas Choice Works in Illinois

Natural gas choice in Illinois looks like electricity choice on the surface — an eligible business can buy the gas supply competitively while the utility delivers it — but the rules differ by territory, and in one large territory the model is entirely different.

Delivery vs. supply for gas

• Delivery — the gas utility owns the pipes and meter, delivers the gas, and handles safety and emergencies. This stays with the utility.
• Supply — the gas commodity, often priced per therm. On utility service it is passed through as a purchased-gas cost that adjusts over time; an eligible business can instead contract supply with a licensed alternative gas supplier.

Where choice works — and where it's different

• Nicor Gas, Peoples Gas, North Shore Gas — eligible commercial customers can choose an alternative gas supplier through each utility's Choices for You program while the utility delivers the gas. See Nicor, Peoples, and North Shore.
• Ameren Illinois gas — there is no standard small-commercial supplier-choice program. Only larger non-residential customers can self-supply through Ameren's Rider T transportation service. In Ameren gas territory (much of central and southern Illinois, including Peoria and Springfield), a "switch your gas supplier" path does not exist for most commercial accounts.

Know your gas utility first

Because the rules are territory-specific, the first step is confirming the gas utility on a recent bill. Chicago is Peoples Gas; most northern suburbs are Nicor; Waukegan and parts of Lake County are North Shore Gas; and some communities (like Buffalo Grove) are split by address.

What to do with this

Confirm your gas utility, then follow the applicable path. For the full overview, see commercial natural gas in Illinois and, for Chicagoland specifics, the natural gas procurement guide.

Why the gas commodity behaves differently than electricity

Two features make commercial gas procurement its own exercise rather than a copy of electricity shopping. First, gas load is usually seasonal — heavily weighted to winter for space heating, though flatter for process or hot-water uses — so a full year of therm usage is needed to price a term fairly, and the shape of that usage matters as much as the total. Second, on utility service the supply cost is a purchased-gas cost that adjusts periodically and passes through without utility markup; a competitive supplier is offering to fix or structure that commodity cost instead. Comparing a supplier's fixed therm price against the utility's adjusting cost is therefore a comparison of certainty versus float, not simply of two rates.

What a business should confirm before shopping gas

Because the rules are territory-specific, the first confirmation is always the gas utility named on a recent bill — Peoples, Nicor, North Shore, or Ameren. That single fact determines whether standard supplier choice even exists (Nicor, Peoples, North Shore) or whether the only path is Rider T transportation for a qualifying larger account (Ameren). From there, the same discipline that applies to electricity applies to gas: gather a year of usage, understand the rate class, compare offers on matched terms and delivery periods rather than on headline per-therm numbers, and read the contract's tolerance and renewal language. Larger or interruptible accounts may have transportation options that change the economics, which is another reason the account's own details drive the decision.

Where to go next

For the statewide overview, see commercial natural gas in Illinois, and for Chicagoland specifics, the natural gas procurement guide. Fold the gas decision into the broader procurement process so electric and gas renewals can be planned together rather than in isolation.

The bottom line

Gas choice in Illinois is real but uneven: it exists as a standard commercial program in Nicor, Peoples, and North Shore territory, and as transportation-only (Rider T) for qualifying larger accounts in Ameren territory. The commodity is seasonal and passed through at cost on utility service, so a supplier is offering certainty on a moving number rather than a guaranteed discount. Confirm the utility, gather a year of usage, and compare on matched terms — the same discipline that governs electricity, applied to a different commodity and a different territory map.

Sources

• Illinois Commerce Commission — Natural Gas Utility authority
• Ameren Illinois — Natural Gas Choice (Rider T transportation)
• Nicor Gas — Our Service Area
• North Shore Gas — Service Area

Retail gas choice does not automatically save money; it is an option to evaluate for a specific account and territory.