Pass-Through Charges: What a Fixed Contract Can Still Change

A fixed price is one of the most reassuring words in a commercial energy quote. It suggests a single number that will not move for the length of the term. But "fixed" describes the energy price, not necessarily every line that can appear on your bill. Many otherwise fixed supply contracts reserve the right to pass certain cost components through to the customer mid-term. If you do not read for those carve-outs, a price you believed was locked can move in ways that surprise you.

This guide explains which components commonly stay variable inside a fixed contract, how to read the language that governs them, and what you can realistically negotiate to narrow it.

What "Fixed" Usually Covers, and What It Often Does Not

When a supplier fixes a price, it is fixing the part of the cost it can hedge — mainly the wholesale energy for your expected volume. That is the number in the pricing exhibit. Around that number sit several other cost categories that the supplier may not be able to lock the same way, and those are the ones that frequently become pass-throughs.

Common categories that a fixed supply contract may still pass through include:

• Change in law or rule. New or increased costs caused by a change in legislation, regulation, tariff, or market-operator rule after the signing date.
• Capacity and transmission reconciliation. Costs tied to the capacity and transmission components can be reconciled or trued up if the underlying charges or your assigned tags change during the term.
• Ancillary and administrative charges. Grid-support services and certain market-operator administrative costs that the wholesale market operator sets and adjusts.
• Taxes and regulatory fees. New or changed taxes, surcharges, or assessments imposed by a government or regulatory body.

Whether any of these actually reach your bill depends on how your specific contract is written. Two quotes at the same headline price can treat these categories very differently — one bundling them into the fixed number, the other reserving them all as pass-throughs.

Why Suppliers Include Pass-Throughs

The logic is the same one behind most risk language: a supplier will only fix a cost it can control or hedge. It can hedge wholesale energy. It generally cannot control what a legislature does, how a market operator changes a rule, or how your capacity tag is recalculated. Asking a supplier to fix a cost it cannot control means asking it to price in a contingency, which raises the number for everyone.

So pass-throughs are not automatically a trap. In many contracts they are a reasonable way to keep the fixed energy price sharp while leaving genuinely uncontrollable costs to flow at actual value. The problem arises when the language is broad, vague, or undocumented — when almost anything can be called a pass-through, or when the customer has no way to verify what was passed through or why.

How to Read the Language

Pass-through terms usually live in two places that you have to read together: the pricing exhibit and the definitions or general terms. The pricing exhibit shows the fixed number; the definitions reveal what that number does and does not include. Reading one without the other is how buyers get surprised.

Work through these questions:

1. Which components are inside the fixed price? Ask the supplier to state, in writing, exactly which cost categories the fixed number covers — energy only, or energy plus capacity, transmission, and ancillary.
2. Which components are reserved as pass-throughs? For each category left out of the fixed price, confirm whether it can be passed through and under what trigger.
3. What triggers a pass-through? A tight clause names specific events — a change in law, a defined reconciliation. A loose clause uses open-ended language like "any cost the supplier incurs," which is far broader.
4. Is there notice and documentation? Does the supplier have to notify you, and to show the basis for a pass-through charge, before or when it applies it?
5. Is there a cap or limit? Some contracts limit pass-throughs to certain categories or amounts. Others leave them open.

Our clause-by-clause contract guide walks through where these terms sit relative to the rest of the agreement, and the Illinois contract red flags list flags the vaguest pass-through wording to watch for.

Where Delivery Charges Fit

It is worth separating two different things that both move during a term. Your supply costs move according to your supplier contract, including any pass-throughs in it. Your delivery costs move through an entirely separate channel. The delivery utility — ComEd in northern Illinois on PJM, or Ameren in central and southern Illinois on MISO — owns the wires, the meter, and the delivery charges, and it always will, regardless of which supplier you use. Delivery rates change through the utility's own regulatory process at the Illinois Commerce Commission, not through your supplier's contract. So when a delivery charge rises, that is not a supplier pass-through; it is a separate, regulated change. Keeping the two straight helps you know which document actually governs a given line on your bill. For product context, see /commercial-electricity/ and /commercial-natural-gas/.

How to Narrow Pass-Through Exposure

You usually cannot delete pass-through language entirely — suppliers include it precisely because it covers costs they cannot control. But you can often make it tighter and more transparent. Reasonable asks include:

• Specific triggers instead of open-ended ones. Replace "any cost the supplier incurs" with named, defined events.
• Notice and documentation requirements. Require the supplier to notify you and show the calculation behind any pass-through, so a charge can be verified rather than taken on faith.
• Category limits. Confirm which cost categories can pass through and get a written statement that others are inside the fixed price.
• A defined reconciliation method. For capacity and transmission, ask how a reconciliation is calculated and how often, so a true-up is predictable rather than arbitrary.

The aim is not to win an unwinnable fight over uncontrollable costs. It is to make sure a "fixed" price is fixed where it can be, and that anything left variable is defined, triggered by specific events, and documented when it moves. For help evaluating and comparing this language across offers, see /commercial-energy-contract-review/. This is general educational information, not legal advice.

Sources

• Illinois Commerce Commission
• PJM
• MISO

This guide is educational and does not promise any specific savings or outcome. Which costs a contract passes through depends on its exact language; confirm the terms with your supplier and the primary sources above.