Municipal Aggregation vs. Individual Retail Supply for Small Businesses

Small commercial accounts in Illinois often have two distinct paths to a competitive electricity supply. One is municipal aggregation, in which the town chooses a supplier for eligible accounts and enrolls them automatically unless they decline. The other is shopping individually, in which the business negotiates its own supply contract. Both affect only the supply portion of the bill, and both leave delivery untouched. The right choice depends on your size, your load, and how much control you want over the terms. This guide explains the mechanics of each and how to think about the fit.

What Municipal Aggregation Is

Municipal aggregation lets a municipality act as a buyer on behalf of its residents and small commercial accounts. The authority comes from a local referendum: voters approve allowing the municipality to negotiate an electricity supply arrangement for eligible accounts within its borders. Once authorized, the municipality solicits offers and selects a supplier, and eligible accounts are enrolled.

The defining feature is that it is usually opt-out. Rather than requiring each account to sign up, the program enrolls eligible accounts automatically and gives them a window to decline. If you do nothing and you are eligible, you are generally in. If you opt out, you stay on whatever arrangement you already have. This structure is what lets aggregation cover a large number of accounts at once, and it is also why eligibility and the opt-out window matter so much to a small business.

How Individual Retail Supply Differs

Shopping individual retail supply is the other path. Here, your business contracts directly with a competitive supplier — an Alternative Retail Electric Supplier (ARES) licensed by the Illinois Commerce Commission — for a rate and terms negotiated for your account. You choose the product (fixed or index), the term length, and you review the specific contract language, from usage bandwidth to renewal terms to fees.

The trade-off is control versus effort. Individual shopping gives you the ability to match a contract to how your facility actually uses power and to compare offers on your own terms. It also puts the work of evaluating suppliers and reading contracts on you. Our guides on how to evaluate an Illinois ARES provider and the ten questions to ask a retail electric supplier exist precisely because individual shopping rewards diligence.

Larger accounts typically shop individually as a matter of course, both because they often fall outside aggregation eligibility and because their size and load make a tailored contract worthwhile. Municipal aggregation is aimed squarely at residents and smaller commercial accounts that benefit from a supplier chosen through a public process.

The One Thing Both Paths Share

Whichever path you take, the delivery side of your service is identical. Aggregation and individual supply both affect only the supply portion of your bill. Your delivery utility — ComEd in northern Illinois, part of the PJM region, or Ameren Illinois in the central and southern parts of the state, part of MISO — continues to own the wires, the meter, and the response to outages, and it bills delivery separately regardless of who supplies your energy. See /utilities/comed/ for how that split appears on a northern Illinois bill. Understanding this keeps the comparison honest: you are choosing among supply arrangements, not changing your physical service.

Weighing the Two for a Small Account

Neither path is universally better. The question is which fits your account.

• Simplicity vs. control. Aggregation is close to automatic — eligible accounts are enrolled, and the municipality did the selection. Individual shopping asks more of you but lets you shape the terms.
• Load profile. A very small, steady account may see little practical difference and value the convenience of aggregation. An account with meaningful size, seasonal swings, or an unusual usage shape often benefits from a contract negotiated to that profile.
• Terms and flexibility. Aggregation offers the terms the municipality negotiated for the group. Individual shopping lets you weigh bandwidth, renewal language, and fees against your own needs. Our guide on comparing commercial energy proposals covers how to line those up.
• The opt-out decision. If your municipality has an active program and you are eligible, the default is enrollment. Treat the opt-out window as a real decision point rather than letting it pass by inattention — even if you conclude that staying in is the right call.
• Eligibility. Confirm your account class. Aggregation eligibility varies, and larger accounts are frequently excluded, which can make the decision for you.

Making the Comparison

A small business that wants to choose deliberately can do a few concrete things. Confirm whether your municipality has an authorized opt-out program and whether your account is eligible. If it does, read the aggregation terms as carefully as you would read a private supply contract — the same questions about bandwidth, term, renewal, and fees apply. Then, if you have the time and the load to justify it, gather a competing individual offer and compare the two on total supply terms, not just a headline rate. Keep in mind that a competitive supplier, whether reached through aggregation or chosen individually, affects only supply; delivery is the utility's either way.

For a small, uncomplicated account, aggregation's simplicity can be exactly the point. For an account with size or an unusual load, the control of individual shopping often earns its extra effort. The Plug In Illinois marketplace and your municipality's program materials are useful starting points, and /commercial-energy-procurement/ covers structured support if you decide to shop.

Sources

• Illinois Commerce Commission
• Plug In Illinois
• ComEd
• Ameren Illinois

This guide is educational and does not promise any specific savings or outcome. Eligibility, program terms, and the fit of aggregation versus individual supply depend on your municipality, your account, and market conditions; confirm the details with your municipality, your supplier, and the primary sources above.