Colleagues, need some help with Missouri law. Ameren Missouri is trying to backbill a commercial client in Springfield for 36 months of undercharged energy costs. They claim a CT ratio error that went undetected. Total backbill is $128,000. I thought Missouri had reasonable limits on backbilling but can't find clear statutory language. Anyone dealt with Ameren on extended backbills?
Missouri backbill limits - Ameren going back 3 years!
Elmer, Missouri doesn't have a specific backbill statute like some states. It falls under general utility commission rules about "reasonable time" for billing corrections. For CT errors, utilities typically can go back further because it's considered their equipment failure. But 36 months seems excessive. What does Ameren's tariff say about billing adjustments?
I fought Alabama Power on a similar CT issue last year. The key is proving when the utility first had notice or should have discovered the error. If Ameren had routine testing schedules for CTs and missed them, you can argue they were negligent in discovering their own equipment problem. What's the CT testing history for this account?
Albert, great point. Ameren's own records show the CT was supposed to be tested in 2014 but wasn't actually tested until late 2015. They're trying to collect from January 2013 forward. If they had followed their testing protocol, the error would have been caught 18 months earlier.
Elmer, that's your defense right there! In Ohio, I've successfully argued that Duke Energy couldn't backbill beyond the point where proper maintenance would have discovered the error. Missouri PSC should apply similar reasoning - utilities can't benefit from their own negligence in equipment maintenance.
The Missouri PSC has been pretty reasonable on backbilling disputes in my experience. File a formal complaint and emphasize Ameren's failure to follow their own testing procedures. Also check if the customer received any estimated bills during this period - that could indicate Ameren knew something was wrong.
What's the customer's load profile look like? Sometimes CT errors create obvious billing anomalies that should trigger utility investigation. If this customer's bills showed dramatic month-to-month variations or unusually low costs compared to similar facilities, Ameren should have investigated sooner.
Warren, the customer is a metal fabrication shop with pretty consistent load. But looking at the billing history, there were several months where the bill was 40-50% lower than typical for similar usage periods. Ameren's customer service even noted "unusual low bill" in their system but apparently never investigated.
That's negligence on Ameren's part. Here in South Dakota, when utilities note billing anomalies but fail to investigate, they lose the right to extensive backbilling. The PSC views it as constructive notice of a problem. Document every instance where Ameren's own systems flagged unusual bills.
Joanne's absolutely right. I'd also request Ameren's internal procedures for investigating billing anomalies. If they have written policies they didn't follow, that strengthens your case significantly. Most utilities have protocols for bills that deviate more than 20-30% from historical usage.
Update: Filed the PSC complaint last week. Ameren's response is due in 30 days. Found their internal policy manual that requires investigation of any commercial bill varying more than 25% from the previous year's same month. They had at least 6 trigger events they ignored. Feeling optimistic about limiting this to 12-18 months max.
Excellent work, Elmer! That internal policy violation should be the nail in the coffin. Pennsylvania has similar utility requirements, and the PUC always sides with customers when utilities don't follow their own procedures. Keep us posted on Ameren's response.