How far back utilities refund overcharges, by state

The short answer

It depends on the state, and the rules are not alike. Of the 17 states verified so far, each against its own statute, rule, tariff or commission statement, the answer runs from one year in Indiana and Oregon to six years in Washington and Wisconsin, and to the whole period of the error in Texas and Florida. Two things decide most claims: whether the state counts back from the date you file or the date the error was found, and whether the start of the error can be dated.

Four ways states set the limit

1. A fixed look-back in the tariff. California's utilities refund three years of a billing error under a tariff rule, or less if the error is known to be shorter.
2. A limit counted from the complaint. Pennsylvania lets the commission order refunds of payments made within four years before a complaint is filed; Illinois counts two years. In these states, the day a claim is filed sets how much is still recoverable.
3. The whole period of the error. Texas and Florida rules require the correction to cover the full period of the overbilling, limited in practice by the records available.
4. Commission practice. Where no statute sets a refund period, as in Kentucky and New York, the commission applies a general limitation period or decides case by case.

Back-billing, where the utility collects for undercharges, usually runs on a different and shorter clock. New York limits non-residential backbills to 12 months when the utility caused the error, and Kentucky limits them to two years. The two periods are not symmetrical, so a refund claim cannot assume the same window.

What this means for a refund claim

• File promptly. In complaint-window states, every month a known error goes unfiled is a month that falls off the refund.
• Date the error. Rules that refund the whole period, or that make an exception when the start can be fixed, reward evidence: the date of the meter exchange, the plant expansion, the account change or the tariff revision.
• Read the tariff's own rule. Most utilities repeat or extend the commission's rule in the rules and regulations section of their tariff, often under a heading on billing or meter error.
• Separate errors from options. A wrong calculation under the assigned rate is a billing error. Moving to a cheaper rate the site always qualified for is often treated differently, and some utilities refund only from the date of the request.
• Keep records. Utilities keep billing records for limited periods, and refunds are often computed from what records remain.

Discovery Energy reviews 36 to 48 months of history on every account and pursues the longest period each jurisdiction allows. See how overcharge recovery works for the steps from finding to refund.

How to check a state that is not listed

1. Search the state administrative code for the commission's rules on billing adjustments, overbilling or meter error.
2. Read the utility's tariff rules for billing error and meter error adjustments.
3. Check the public utility statute for sections on refunds, reparations or complaints, which often hold the time limit.
4. Ask the commission's consumer staff how the limit is applied to non-residential customers. Each regulator is linked in the table above.

Sources

• Arkansas: Arkansas PSC billing rules, as the Commission summarizes them
• California: PG&E Electric Rule 17.1 and Gas Rule 17.1, under rules the CPUC set in Decision 86-06-035
• Colorado: 4 CCR 723-4, Rule 4402 (gas utilities), as quoted by the utility; rules text
• Florida: Rule 25-6.106(2), F.A.C. (electric); Rule 25-7.0851 (gas)
• Illinois: 220 ILCS 5/9-252, 9-252.1 and 83 Ill. Adm. Code 280
• Indiana: 170 IAC 5-1-14 (gas) and 170 IAC 4-1-14 (electric meter adjustments)
• Kentucky: No refund statute; Public Service Commission practice, as described by its Executive Director in 2023
• Michigan: Mich. Admin. Code R 460.126a (billing error) and R 460.115 (meter error)
• Minnesota: Minn. R. 7820.3800 (electric) and 7820.4000 (gas)
• Missouri: 20 CSR 4240-13.025
• New York: Public Service Law §118(3); 16 NYCRR 13.9 for non-residential backbills
• Ohio: Ohio Adm. Code 4901:1-10-05 (meter inaccuracy)
• Oregon: ORS 757.077(3) and OAR 860-021-0135
• Pennsylvania: 66 Pa.C.S. §1312(a)
• Texas: 16 TAC §25.28(c) (electric utilities) and §25.480 (retail electric providers)
• Washington: WAC 480-90-178 (gas) and WAC 480-100-178 (electric)
• Wisconsin: Wis. Adm. Code PSC 113.0406; Wis. Stat. 893.93(1)(a) as applied in utility rules
• Pennsylvania PUC national list of utility commissions