Starting Thursday, customers in the state will face shutoffs if they are behind three months or more in payments, they haven't made bill-paying arrangements or they're not identified as customers, Ameren spokesman Shelley Epstein said.

Next week, Ameren will begin cutting service to customers who not only haven't paid bills in three months, but who have a debt of more than $2,000, Epstein said Wednesday.

Ameren has already applied credits from its $1 billion rate-relief rebate program to the accounts, but past-due balances still remain. Some customers owe more than $4,000, and others haven't made a payment in a year. And there are customers who have set up service, and then haven't paid knowing the utility won't disconnect in the winter.

"There are some we have contacted more than 10 times by either phone or notice, and other folks agreed to a payment agreement and then immediately broke it," he told the Peoria Journal Star.

Ameren officials say the disconnects are a last resort, and they are urging delinquent customers to contact the utility to arrange a payment plan or to apply for financial aide and local aid agencies.

Epstein said the specific number of delinquent customers is unavailable because it fluctuates as customers pay their bills.

Ameren held off on starting its planned disconnects in April while the utility negotiated with Illinois lawmakers over how to handle the spike in electric rates. After reaching a $1 billion rate-relief rebate agreement with legislators, the utility decided to wait for those checks or credits to go through customers accounts before beginning shutoffs, Epstein said.