Texas · Public Utility Commission of Texas (PUCT)

Auditing Oncor commercial bills

North, Central and West Texas within ERCOT, including Dallas, Fort Worth, Waco, Midland and Odessa.

Oncor is a transmission and distribution utility (TDU) in the ERCOT market. It does not sell electricity or send bills to retail customers in its competitive area. Commercial customers choose a retail electric provider (REP), and the REP bills them for energy along with Oncor's delivery charges, which the REP passes through from Oncor's Tariff for Retail Delivery Service. Those delivery charges are set by Oncor rate class, such as Secondary Service Less Than or Equal to 10 kW and Secondary Service Greater Than 10 kW, and they include customer, metering, distribution system and transmission cost recovery charges. Because the REP bill shows TDU charges as pass-through lines, many AP teams never check them against Oncor's tariff. For larger accounts, transmission charges depend on 4CP demand, the site's demand during ERCOT's monthly system peaks from June through September of the prior year. For multi-site operators, rate class assignment, billing kW and 4CP values are where we find most delivery charge errors.

Practice notes

Audit Oncor charges on the REP bill as pass-through lines. Compare each TDU line with Oncor's tariff for the account's rate class and the billing determinants Oncor sent to the REP. Some REP contracts pass TDU charges through at cost and others bundle them, so the contract determines how a TDU error flows back to the customer.

Check 4CP demand every January, when Oncor resets it from the prior summer's four ERCOT monthly peaks. A site that ran backup generation tests or had a meter problem during a peak interval can carry an inflated value for the whole year. Interval data at the peak timestamps shows whether the value is right.

When a site closes, the REP must submit a move-out to Oncor through ERCOT market transactions. If that request is never sent, delivery charges continue under the old account. We document the closure date with the lease surrender and final read, and work with the REP to correct the account and recover charges after the closure.

Back-billing and refunds

In areas of Texas with customer choice, 16 Texas Administrative Code §25.126 sets rules for adjustments when a TDU finds a meter or metering equipment that does not meet accuracy standards. It limits the period Oncor can back-bill for additional charges, with a longer limit where meter tampering is involved, and it bars back-billing for periods when the current customer or REP was not of record. Overcharges reach the customer as corrected TDU charges that the REP passes through. Because the REP sends the bill, claims typically start with the REP and Oncor corrects the underlying delivery data.

Findings we see most often

Demand ratchet errors
Billing kW held at a prior peak beyond what the tariff allows, or based on a peak recorded during a meter fault.
Wrong rate schedule
Accounts assigned to the wrong Oncor rate class, or REPs billing TDU charges for a different class than Oncor applied.
Meter multiplier errors
IDR meters on CT-rated services billed with a multiplier that does not match the installed transformers.
Closed and vacant site billing
REP and TDU charges continuing at closed sites because the move-out was never sent.

Commercial schedules we check

Schedule	Applies to	What we check
Secondary Service Less Than or Equal to 10 kWOncor tariff rate class, small secondary	Small commercial accounts at secondary voltage with demand of 10 kW or less, billed through the REP.	Confirm the account belongs in this class and that the REP passes through the current Oncor customer, metering and distribution charges without markup the contract does not allow.
Secondary Service Greater Than 10 kWOncor tariff rate class, secondary demand	Commercial accounts at secondary voltage with demand above 10 kW, billed through the REP.	Rebuild billing kW from interval data, including any carry-forward of prior peaks under the tariff, and check whether transmission charges use NCP kW or 4CP kW as the tariff requires.
Primary Service Greater Than 10 kWOncor tariff rate class, primary demand	Larger accounts taking service at primary voltage, billed through the REP.	Verify the metering point, voltage level and 4CP demand used for transmission cost recovery charges.
Transmission ServiceOncor tariff rate class, transmission voltage	Large industrial accounts taking service at transmission voltage.	Check 4CP demand against the site's interval data at the ERCOT monthly peak intervals for June through September of the prior year.

Schedule names and eligibility summarized from the utility's published tariff. The utility's current tariff book governs.

Oncor questions

Oncor is a transmission and distribution utility. In ERCOT's competitive market, your retail electric provider bills you and passes Oncor's delivery charges through.

Oncor corrects the delivery charges it sent to the REP, and the REP credits or refunds you under your contract.

Your site's average demand during ERCOT's monthly system peak intervals in June through September of the prior year. It sets transmission charges for larger accounts for the following year.

Audit your Oncor accounts.

Connect bills for up to 50 meters. Get the findings report in about three weeks. Pay nothing unless money comes back.

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from bill access to first findings report: 21 daysfrom bill access to first findings report
of filed claims accepted by the utility in full or in part: 94%of filed claims accepted by the utility in full or in part