Client in Chattanooga has an EPB account at a facility that straddles the city-county line. EPB is charging Hamilton County sales tax rate but the client's service address is technically inside the Chattanooga city limits which has a different combined rate. The difference is about 0.25% but on a $6,000/month electric bill that's $15/month — not huge but it's been wrong for years. Does this happen often?
Utility charging the wrong sales tax rate — state rate vs local rate confusion
More often than you'd think. I've seen it in Chattanooga and in the Nashville area where Davidson County and surrounding counties have different tax rates. The utility sets the tax rate based on the service address in their billing system. If the address was entered incorrectly or the jurisdiction boundary changed, the wrong rate gets applied indefinitely. It's a small per-month error but over 5-10 years it adds up. I check the tax rate on every bill I audit by looking up the actual combined rate for the service address on the state Department of Revenue website.
Andre and Lorraine identify a subtle but real category of tax errors. Sales tax rates are location-specific and utilities rely on their billing system's address coding to apply the correct rate. When addresses are miscoded or jurisdictions change, the wrong rate gets locked in. This is especially common for properties near municipal boundaries, in recently annexed areas, or in special tax districts. Checking the tax rate against the actual jurisdiction is a quick verification step that should be standard in every audit. The error is always systemic — every bill has the wrong rate until someone catches it.
EPB corrected the rate and issued a 36-month refund. Only about $540 total but combined with other findings on the same account the overall engagement was solid. The tax rate check now takes me about 2 minutes per account and has caught errors on 3 other clients since.