A school district business manager sent us an invoice last November with a note: “This looks high, can you check it?” We asked for the contract. He had it. We asked for the twelve months before the contract started. He had eight. We asked which rate class the meter was on. He didn’t know, and neither did the person who signed the contract.
There was nothing to check. Not because the invoice was fine — we never found out — but because an invoice is a claim, and a claim can only be tested against records that exist somewhere other than the invoice.
Five documents make that test possible. Each one answers a question the others can’t, and the invoice is what you run them against.
Document one: the quote worksheet, with its assumptions intact
Not the winning quote. The worksheet — the comparison as it stood when the decision was made, including the volume assumption, the term, the load shape used, the tax treatment assumed, which components were quoted as included and which as pass-through, and who was bidding.
This is the document people throw away, and it’s the one that answers the question “what were we told we were buying?” A price without its assumptions is not a price. If the comparison assumed 4.2 million kWh and the facility used 3.1 million, a supplier’s swing or deviation terms may be operating, and you will not be able to reconstruct that from the invoice.
Keep the version, the date, and the compensation disclosure. Under 16 TAC §25.486, a broker must disclose how it will be compensated and by whom before services begin, renew, or materially change. That disclosure belongs in this folder for the same reason the price assumptions do: it is part of the record of what was represented.
Document two: the load file
Twelve consecutive months of usage, by meter, with ESI IDs, meter type, and interval data where the meter produces it.
Why twelve and not four: because a four-month sample can’t distinguish a seasonal shape from a permanent change in operations, and because twelve is the period the state uses for related purposes — the Comptroller requires a person claiming single-meter predominant use for an exempt function to establish that use over twelve consecutive months.
Why interval data matters: an interval-metered account’s demand, load factor, and coincident usage can be observed directly. A non-interval account’s consumption is allocated across settlement intervals using an ERCOT load profile rather than a personal meter. ERCOT publishes actual and backcasted profiles giving 15-minute kWh values for every profile type and weather zone. If your account is profiled, you should know it, because your supplier’s risk on your account is being estimated rather than measured, and that is priced.
The load file answers: what did this building actually do, and is this month’s invoice consistent with it?
Document three: the delivery tariff and rate class
The TDSP, the rate class, and the current tariff. Not a memory of the rate class — the tariff sheet.
Delivery charges are regulated and territory-specific, and the PUCT publishes rate summaries submitted monthly by the utilities. The scale is not trivial. In the PUCT’s September 1, 2026 summary, illustrative residential delivery bills at 1,000 kWh ran $61.07 for AEP Central, $59.93 for AEP North, $69.03 for CenterPoint, $64.36 for Oncor, and $81.87 for TNMP. Those are residential, and your commercial class is a different schedule — which is exactly the point. You cannot audit a delivery line against a number you half-remember from a different territory.
For interval-metered commercial classes, the tariff also carries the transmission demand component. Oncor’s September 2026 secondary greater-than-10-kW IDR class showed $6.050798 per 4CP kW; CenterPoint’s secondary greater-than-10-kVA IDR class showed $6.177655 per 4CP kVA. Those figures belong to those classes in that period and nowhere else.
This document answers: is the account billed under the right tariff and rate class, and is the delivery portion of the invoice arithmetic that reconciles?
Document four: the executed contract and its price schedule
The signed agreement, with the price schedule attached and legible.
For small commercial accounts under 16 TAC §25.475, the contract is defined: the Terms of Service, the Electricity Facts Label, the Your Rights as a Customer document, the enrollment documentation, and where applicable a prepaid disclosure statement. Larger C&I contracts are bespoke, which makes the price schedule more important rather than less. It should state the nominated volume or load-shape basis, the settlement point reference, congestion treatment, losses, unaccounted-for energy, ancillary service charges, 4CP and delivery demand exposure, credit and collateral, swing and deviation terms, force majeure, tax treatment, change in law, renewal, and termination.
A note on one recurring dispute. Unaccounted-for energy is not a discretionary supplier surcharge. ERCOT calculates UFE each settlement interval as total generation supplied less total system load plus losses, then allocates it to loads. Whether it reaches your invoice is a contract question. Whether it exists is not.
This document answers: what did we actually agree to pay for, component by component?
Document five: the tax record
The legal purchaser, the exemption basis if any, the predominant use study and its period if there is one, and the certificate given to the provider.
The starting presumption in Texas is that furnishing electricity is a sale of tangible personal property and is presumed taxable. Exemption requires documentation, and it attaches to a purchaser and a use rather than to a label. A nonresidential lessor is the consumer and may not claim exemption based on a lessee’s exempt status or use — so for leased space, establish who buys the power before assuming anything.
If tax has been charged in error, the Comptroller’s route runs through the provider first, with an Assignment of Right to Refund available, and the general limitations period is four years from when the tax was due and payable. That is a workflow with a deadline attached, which is a reason to keep the record current rather than reconstruct it later.
This document answers: is the tax line on this invoice correct for this purchaser and this use?
Running the audit
Put the five in one folder, then take the invoice and ask four questions in order.
Is the volume consistent with the load file, adjusted for weather and operations? Is the supply price what the contract’s price schedule produces for that volume? Is the delivery portion what the tariff and rate class produce for that demand? Is the tax line correct for the purchaser and the documented use?
Most variances resolve at question one or three, which is worth knowing before you call a supplier about question two. The PUCT’s rate page itself tells customers to contact the reporting utility for specific rate questions — generic tariff advice has limits, and the utility is the right party for a delivery dispute.
The strongest objection
The serious pushback is that this is over-engineered. The contract is the agreement. Invoices are generated by supplier systems against that agreement. If a number looks wrong, call the supplier, have them explain it, and if they’re wrong they’ll fix it. Maintaining a five-document folder for every account is administrative work that produces nothing most months, and most organizations have better uses for that time.
Most months, that’s right. The folder produces nothing, and a phone call resolves the ordinary error faster than a file review would.
The objection breaks in two specific situations, and they’re the expensive ones.
The first is when the variance isn’t a supplier error at all — it’s a rate class change, a meter reconfiguration, a tax status that quietly stopped applying, or a usage pattern that drifted past a contract threshold. In those cases the supplier’s explanation is correct and the invoice is still costing you money you could have avoided. A call to the supplier cannot surface a problem that isn’t the supplier’s.
The second is when there’s a genuine dispute and the relevant person has left. Contract administration in commercial buildings turns over. The reason to keep the quote worksheet and the load file is not that you’ll read them next month; it’s that in month twenty-two, when the account manager who signed is gone and the supplier’s position is that the pricing always worked this way, the folder is the only thing that can say otherwise.
The honest cost-benefit is that this takes about an hour at contract execution and ten minutes at renewal, and it buys you the ability to be specific in the one conversation per term where specificity is worth something. That’s a defensible trade. It is not a claim that the folder saves money on its own, and anyone who sells it that way is overselling a filing cabinet.
Amerigy Energy is a registered electricity broker in Lufkin, PUCT registration #BR190721. Building the folder is the least interesting part of what we do and usually the part clients thank us for two years later.
References
1. Public Utility Commission of Texas, 16 Tex. Admin. Code §25.486, Customer Protections for Brokerage Services, effective July 19, 2023. https://ftp.puc.texas.gov/public/puct-info/agency/rulesnlaws/subrules/electric/25.486/25.486.pdf
2. Public Utility Commission of Texas, 16 TAC §25.475, General Retail Electric Provider Requirements and Information Disclosures to Residential and Small Commercial Customers, effective January 6, 2022. https://ftp.puc.texas.gov/public/puct-info/agency/rulesnlaws/subrules/electric/25.475/25.475.pdf
3. Electric Reliability Council of Texas, Load Profiling, accessed September 12, 2026. https://www.ercot.com/mktinfo/loadprofile
4. Electric Reliability Council of Texas, UFE Analysis Reports, accessed September 12, 2026. https://www.ercot.com/mktinfo/data_agg/ufe
5. Public Utility Commission of Texas, Transmission and Distribution Utility Rates, as of September 1, 2026. https://www.puc.texas.gov/industry/electric/rates/tdr/Default.aspx
6. Oncor Electric Delivery Company LLC, PUCT Monthly Report, as of September 1, 2026. https://ftp.puc.texas.gov/public/puct-info/industry/electric/rates/tdr/tdu/Oncor_Rate_Report.pdf
7. CenterPoint Energy Houston Electric, LLC, CenterPoint Energy Houston Electric Rates Report, September 1, 2026. https://ftp.puc.texas.gov/public/puct-info/industry/electric/rates/tdr/tdu/CenterPoint_Rate_Report.pdf
8. Texas Comptroller of Public Accounts, Natural Gas and Electricity, Part Two: Nonresidential and/or Commercial Use, Tax Policy News, April 2021. https://comptroller.texas.gov/taxes/tax-policy-news/2021-april.php
9. Texas Comptroller of Public Accounts, 34 Tex. Admin. Code §3.295 — Natural Gas and Electricity, reproduced by Cornell Legal Information Institute. https://www.law.cornell.edu/regulations/texas/34-Tex-Admin-Code-SS-3-295