Chubu Electric Power Overcharged About 5 Million Users Due to Calculation Error

This is a reminder that billing integrity at large utilities is an operational risk, not just a customer-service one. The scale — roughly 5 million accounts over more than two years — matters because it touches nearly every household in the utility's service area, and small per-month amounts add up to a material remediation exercise. The open question is how the company handles refunds and whether the disclosure prompts any review of metering and billing systems at other Japanese utilities.