Customer Handbook


The Electric Service Customer Choice and Rate Relief Law became effective in late 1997. This law allows customers the option to choose who supplies their electricity. The combined services traditionally provided by the local electric utility have been divided into parts - the regulated electric utility continues to deliver electric power over the wires using their transmission and distribution facilities. However, the power running through those wires is sold to a customer by the company of that customer’s choice: the customer’s utility or an alternative Retail Electric Supplier (RES, a.k.a. “Supplier”). A customer can choose to continue to purchase power from Ameren Illinois, or can buy power from a Supplier.

Regardless of whether a customer chooses a Supplier, Ameren Illinois will continue to deliver the electricity and to offer quality service. A customer should always call Ameren Illinois to report power quality problems, power outages, or downed power lines. Ameren Illinois customer service representatives can also answer questions concerning electric choice issues.

Contact Ameren Illinois at 800.755.5000.

Energy Supply Options (Residential)

Customers of Ameren Illinois have three options for their energy supply. The Basic Generation Service (BGS) option is described below.
Basic Generation Service (BGS)
This default supply option represents the energy price obtained by Ameren Illinois through the independently managed and state-monitored (Illinois Commerce Commission) auction.
More about the BGS energy supply option:


  • Energy is provided to the customer at a fixed price by Ameren Illinois.
  • Service is for residential and small non-residential customers who do not choose a Retail Electric Supplier (RES).
  • Service does not include summer and non-summer charges.
  • Rider BGS - Basic Generation Service

Energy Supply Options (Residential)

Customers of Ameren Illinois have several options for their energy supply.

Real Time Pricing (RTP)

Real Time Pricing is an option that allows customers (except DS-5 optional outdoor protective lighting customers) to pay fluctuating hourly market price for electricity.

More about the RTP energy supply option:

  • Energy priced at actual hourly MISO Day-Ahead Locational Marginal Prices (LMP) and provided by Ameren Illinois.
  • Customers are required to have Interval Metering before this option can be selected.
  • Option allows unlimited switching to and from Retail Electric Suppliers (RES) within Direct Access Service Request (DASR) rules.

Power Smart Pricing (PSP)

Power Smart Pricing is an experimental program that provides enhanced customer service and energy cost comparison tools for residential hourly pricing customers.

More about the PSP program:

  • Administered by Elevate Energy, a non-profit organization dedicated to helping people and communities manage their energy costs.
  • Uses the same day-ahead hourly pricing as Real Time Pricing.
  • PSP offers enhanced energy management tools such as High Price Alerts and the Bill Comparison tool.

Learn more about Power and Energy Supply Riders for RTP and PSP.

Energy Supply Options (Residential)

Customers of Ameren Illinois have three options for their energy supply. The Retail Electric Supplier (RES) option is described below.

Retail Electric Supplier (RES)
An alternative Retail Electric Supplier (RES) supplies electricity to customers in Ameren Illinois' service territory. The electricity from the supplier is delivered to the customer via Ameren Illinois' distribution lines.

Although you may choose another company to supply energy service, your bill will include Ameren Illinois’ delivery service charges (e.g. charges for maintaining the distribution lines that deliver the electricity). However, since the RES is selling the electricity flowing through Ameren Illinois’ distribution lines to the customer’s home, the RES determines the rate (i.e. price per kilowatthour) for the electricity supply charges.

There are several suppliers from which to choose. A current listing of suppliers registered with Ameren Illinois can be found on the Suppliers Registered with Ameren page.

Different suppliers offer different billing options. Some directly bill their customers for electric supply charges, leaving Ameren Illinois to separately bill the same customer for Ameren Illinois’ delivery services charges. Other suppliers package both their own electric supply charges with Ameren Illinois' delivery services charges into one single bill. Still other suppliers send their electric supply charges to Ameren Illinois so that Ameren Illinois can bill both electric supply charges and Ameren’s delivery services charges in a single bill.

Switching to a Supplier

A Supplier may contact a prospective customer by phone, by mail, or in-person. If a customer wishes to contact a Supplier, a list of Suppliers registered with Ameren Illinois and certified by the Illinois Commerce Commission to supply commercial and industrial accounts can be found on the Suppliers Registered with Ameren page.

When a customer is considering switching to a Supplier, the Supplier will ask the customer for certain pieces of information (e.g. name, billing address, service address, Ameren Illinois account number, meter number). The customer should provide this information to a Supplier if the customer is interested in switching to the Supplier’s service. The switch to a Supplier cannot be completed until all terms and conditions have been explained, and the customer has provided authorization for the switch. The valid forms of authorization are a written signature, electronic signature, or a recorded third party verification performed over the phone. Once a customer has agreed to switch to a Supplier, the Supplier will submit an electronic enrollment transaction to Ameren Illinois. If the enrollment transaction is accepted (i.e. it contains a valid account number), Ameren Illinois is authorized to release a range of customer data to that Supplier, including the customer’s historic and ongoing electricity usage data.

Customer Information

Once an enrollment to a Supplier is effective, the Supplier will begin receiving ongoing monthly usage data. A customer may also request, or the Supplier may request per a separate written authorization from the customer, billing data including revenues and payment history.

An Ameren Illinois account number is the validation criteria needed for a Supplier to enroll a customer’s account. This means that the Supplier must have this number correct in order to successfully submit the enrollment to Ameren Illinois. A customer should not give an account number to a Supplier unless the customer is considering switching to the Supplier.

Ameren Illinois will not accept personal information changes to a customer’s account from a Supplier unless the customer has signed an Agency Agreement designating the Supplier as the customer’s agent.

Effective Date of Enrollment to a Supplier
An enrollment will take place on a customer’s account’s next scheduled meter reading date and in accordance with the terms of the contract with the Supplier.

Ameren Illinois will honor the first enrollment request received from a Supplier. If Ameren Illinois receives a second enrollment request from another Supplier before the first enrollment is activated, then the second enrollment request will be rejected.

The enrollment transaction from the Supplier must be processed by Ameren at least ten calendar days plus two business days (but no more than 45 calendar days) prior to the account’s next scheduled meter reading date.


When a Supplier submits a valid enrollment request to Ameren Illinois, Ameren Illinois will send a letter notifying the customer of the impending enrollment. If the enrollment information on the notification letter is incorrect, or if the customer has changed his/her mind regarding the enrollment, then the customer must notify Ameren Illinois as soon as possible. Specifically, the customer has ten calendar days from the date that Ameren Illinois processes the Supplier’s enrollment to contact Ameren Illinois and request a rescission of the pending enrollment. The last day of the ten calendar day rescission window is stated in the customer enrollment letter. Note that a Supplier may assess a fee to the customer for rescinding the Supplier’s enrollment.

Loss of Service

Ameren Illinois has no responsibility for claims, damages or losses resulting from a customer’s relationship with a Supplier regarding delivery or non-delivery of energy or energy services.

If the Illinois Commerce Commission revokes a Supplier’s certificate or the supplier materially defaults in its service agreement, then Ameren Illinois will notify that Supplier’s customers as quickly as possible regarding the change and the available supply options.

If a Supplier stops doing business, then that Supplier’s residential accounts will be placed on Ameren Illinois BGS supply.

Payment Provisions for Accounts Enrolled With a Supplier

Delivery Services Charges
Each customer with an account enrolled to a Supplier pays a fee for delivery services based on Ameren Illinois’ costs for providing service and the customer’s own usage. The prices are stated in tariffs approved by the Illinois Commerce Commission.

Delivery services bills from Ameren Illinois include detailed information such as itemized listings for delivery services charges as well as energy and public purpose program charges. Charges for public purpose programs have been part of Ameren Illinois' bills since January 1, 1998. Public purpose programs help low-income customers and support development of renewable energy.

A Supplier may offer a prospective customer one or more of the following billing options from which to choose: 


  • Dual Billing - The customer receives two bills: One bill from Ameren Illinois for its delivery services charges, and a separate bill from the Supplier for the its electric supply charges.
  • Single Bill Option - The Supplier consolidates its electric supply charges and Ameren Illinois' delivery services charges so that the customer receives one bill.
  • Utility Consolidated Billing - Ameren Illinois consolidates its delivery services charges and the Supplier’s electric supply charges so that the customer receives one bill.

Regardless of the billing option, Ameren Illinois’ bill due dates, late pay charges, and collection activities will not change.

When a customer’s account is enrolled to a Supplier and is placed on Dual Billing, the customer will have the same payment options available to pay for the Ameren Illinois delivery services portion of the bill as were available prior to the enrollment. Payments can be made via CheckFree, DirectPay, SpeedPay, or by "traditional" mail-in check. 
When a customer’s account is enrolled to a Supplier and is placed on the Single Bill Option, the Supplier expects payment from the customer for the Ameren Illinois delivery services charges. The Supplier, upon receipt of a customer payment, forwards any amount due to Ameren Illinois to Ameren Illinois. Note that the law states that partial payments from the customer to a Supplier must first be applied to Ameren Illinois' delivery services charges.
When a customer’s account is enrolled to a Supplier and is placed on Utility Consolidated Billing, the customer will have the same payment options available to pay for the Ameren Illinois delivery services charges and the Supplier’s charges as were available prior to the enrollment. See Billing & Payments options.

When a customer switches to a Supplier, the rules for payment due dates for Ameren Illinois' charges do not change. However, payment due dates for Supplier charges (billed via dual billing or the Single Bill Option) will be dictated by the contract terms of the agreement that the customer signed with the Supplier.

If a customer has a question concerning delivery services fees or is having difficulty paying Ameren Illinois delivery services charges in full, then the customer should contact Ameren Illinois to request a deferred payment agreement. The customer will receive, in writing, a copy of any settlement agreement extending beyond 60 days. If a customer has a payment issue with the Supplier’s charges, then the customer must work that problem out with the Supplier.

Disputes and Complaints

For problems that a customer is unable to resolve with Ameren Illinois or its Supplier, the customer may contact the Illinois Commerce Commission (ICC) or the Illinois Attorney General.

The ICC may be contacted by phone at 800.524.0795 or via the internet at When contacting the ICC, a customer can also request additional electric choice information.

The Illinois Attorney General may be contacted by phone at 312.814.3000 (northern Illinois) and 217.782.1090 (central and southern Illinois).
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