Vistra Corp.

3. REVENUE

Revenue Disaggregation

The following tables disaggregate our revenue by major source:

(a)Represents net capacity sold (purchased) in each ISO/RTO. The East segment includes $793 million of capacity sold offset by $566 million of capacity purchased. Net capacity purchased in each ISO/RTO, as applicable, included in fuel, purchased power costs, and delivery fees in the consolidated statement of operations includes capacity purchased of $130 million offset by $63 million of capacity sold within the East segment.

(b)Represents transferable PTCs generated from qualifying nuclear and solar assets during the period.

(c)East segment includes $147 million of intersegment unrealized net losses, and Texas segment includes $293 million of intersegment unrealized net gains from mark-to-market valuations of commodity positions with the Retail segment.

(a)Includes ten months of revenue associated with operations acquired in the Energy Harbor Merger.

(b)Represents net capacity sold (purchased) in each ISO/RTO. The East segment includes $126 million of capacity sold offset by $52 million of capacity purchased. Net capacity purchased in each ISO/RTO, as applicable, included in fuel, purchased power costs, and delivery fees in the consolidated statement of operations includes capacity purchased of $139 million offset by $116 million of capacity sold within the East segment.

(c)Represents transferable PTCs generated from qualifying nuclear and solar assets during the period.

(d)East segment includes $195 million of intersegment unrealized net losses, and Texas and West segments include $74 million and $4 million, respectively, of intersegment unrealized net gains from mark-to-market valuations of commodity positions with the Retail segment.

(a)Represents net capacity sold (purchased) in each ISO/RTO. The East segment includes $233 million of capacity sold offset by $135 million of capacity purchased. Net capacity purchased in each ISO/RTO, as applicable, included in fuel, purchased power costs, and delivery fees in the consolidated statement of operations includes capacity purchased of $82 million offset by $73 million of capacity sold within the East segment.

(b)East segment includes $814 million of intersegment unrealized net gains and Texas and West segments include $48 million and $6 million, respectively, of intersegment unrealized net losses from mark-to-market valuations of commodity positions with the Retail segment.

Retail Energy Charges

Revenue is recognized when electricity is delivered to our customers in an amount that we expect to invoice for volumes delivered or services provided. Sales tax is excluded from revenue. Payment terms vary from 15 to 60 days from invoice date. Revenue is recognized over-time using the output method based on kilowatt hours delivered. Energy charges are delivered as a series of distinct services and are accounted for as a single performance obligation.

Energy sales and services that have been delivered but not billed by period end are estimated. Accrued unbilled revenues are based on estimates of customer usage since the date of the last meter reading provided by the independent system operators or electric distribution companies. Estimated amounts are adjusted when actual usage is known and billed.

As contracts for retail electricity can be for multi-year periods, the Company has performance obligations under these contracts that have not yet been satisfied. These performance obligations have transaction prices that are both fixed and variable, and that vary based on the contract duration and customer type. For the fixed price contracts, the amount of any unsatisfied performance obligations will vary based on customer usage, which will depend on factors such as weather and customer activity and therefore it is not practicable to estimate such amounts.

Wholesale Generation Revenue from ISOs/RTOs and Revenue from Other Wholesale Contracts

Wholesale generation revenue is recognized when volumes are delivered to the ISO/RTO. Other wholesale contracts include other revenue activity with the ISO/RTO, such as ancillary services, auction revenue, neutrality revenue and revenue from nonaffiliated retail electric providers, municipalities or other wholesale counterparties. Wholesale revenues are recognized over time using the output method based on kilowatt hours delivered or other applicable performance measurements and cash is settled shortly after invoicing. Vistra operates as a market participant within ERCOT, PJM, ISO-NE, NYISO, MISO and CAISO and expects to continue to remain under contract with each ISO/RTO indefinitely. Wholesale revenues are delivered as a series of distinct services and are accounted for as a single performance obligation. When electricity is sold to and purchased from the same ISO/RTO in the same period, the excess of the amount sold over the amount purchased is reflected in wholesale generation revenues.

Capacity Revenue From ISO/RTO

We offer generation capacity into competitive ISO/RTO auctions in exchange for revenue from awarded capacity offers. Capacity ensures installed generation and demand response is available to satisfy system integrity and reliability requirements. Capacity revenues are recognized when the performance obligation is satisfied ratably over time as our power generation facilities stand ready to deliver power to the customer. Penalties are assessed by the ISO/RTO against generation facilities if the facility is not available during the capacity period and are recorded as a reduction to revenue. When capacity is sold to and purchased from the same ISO/RTO in the same period, the excess of the amount sold over the amount purchased is reflected in capacity revenue from ISO/RTO.

Other Revenues

Other revenues, as included in the tables of disaggregated revenue above, represent amounts not accounted for under ASC 606, Revenue from Contracts with Customers and are comprised of the following:

•Transferable production tax credit revenues accounted for as grants related to income by analogy to ASC 832 (see Note 5 for additional information).

•Intangible amortization of acquired intangible liabilities related to retail and wholesale contracts (see Note 9 for additional information).

•Hedging revenue from electricity and natural gas derivative contracts accounted for under ASC 815, Derivatives and Hedging, including the impact of realized and unrealized gains or losses on those contracts (see Note 13 for additional information).

•Intersegment sales are presented by segment and eliminated in consolidation.

Contract and Other Customer Acquisition Costs

We defer costs to acquire retail contracts and amortize these costs over the expected life of the contract. The expected life of a retail contract is calculated using historical attrition rates, which we believe to be an accurate indicator of future attrition rates. The deferred acquisition and contract cost balance as of December 31, 2025 and 2024 was $129 million and $114 million, respectively. The amortization related to these costs during the years ended December 31, 2025, 2024 and 2023 totaled $111 million, $97 million, and $88 million respectively, recorded as SG&A expenses, and $7 million, $6 million, and $6 million, respectively, recorded as a reduction to operating revenues in the consolidated statements of operations.

Practical Expedients

The majority of our revenues are recognized under the right to invoice practical expedient, which allows us to recognize revenue in the same amount that we have a right to invoice our customers. Unbilled revenues are recorded based on the volumes delivered and services provided to the customers at the end of the period, using the right to invoice practical expedient. We have elected to not disclose the value of unsatisfied performance obligations for contracts with variable consideration for which we recognize revenue using the right to invoice practical expedient. We use the portfolio approach in evaluating similar customer contracts with similar performance obligations. Sales taxes are not included in revenue.

Performance Obligations

As of December 31, 2025, we have future fixed fee performance obligations that are unsatisfied, or partially unsatisfied, relating to capacity auction volumes awarded through capacity auctions held by the ISO/RTO or capacity contracts with customers for which the total consideration is fixed and determinable at contract execution. Capacity revenues are recognized when the performance obligations to provide capacity to the relevant ISOs/RTOs or counterparties are fulfilled. Amounts with counterparties in the table below represent minimum guaranteed capacity revenues as determined on a contract by contract basis and do not represent the full amount of capacity that is expected to be delivered.

Trade Accounts Receivable

Gross trade accounts receivable as of December 31, 2025 and December 31, 2024 include unbilled retail revenues of $924 million and $802 million, respectively.

Allowance for Credit Losses on Accounts Receivable