Tucson Electric Power is providing a credit to some customers using Time of Use pricing plans because their on-peak usage was miscalculated due to an error that has since been resolved.

In some cases when a meter was unable to collect usage data during short intervals – perhaps due to storm damage or a cellular service outage – our systems mistakenly applied on-peak rates to subsequent off-peak usage. This programming error only affected usage since March 2022 and has been resolved.

After a close review of all customer data on those plans, we identified about 1,600 of TEP’s 438,000 customers who may have experienced discrepancies.

To correct this error, we will apply lower, off-peak rates to all missing on-peak usage in the affected bill cycles for residential and small business customers. The average bill credit will be less than $5 for most residential customers, with some exceptions.

TEP sent an email to affected customers Friday and will reach out to the limited number of medium and large commercial customers affected by this issue.

We’re committed to the use of fair and accurate billing procedures and apologize for any inconvenience this incident has caused. Affected customers will see the credit on their next bill.