General, Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2024

Accounting Policies [Abstract]

Principles of consolidation [Policy Text Block]

Principles of Consolidation

Williams’ consolidated financial statements include the accounts of all entities that Williams controls and its proportionate interest in the accounts of certain ventures in which it owns an undivided interest. Management’s judgment is required to evaluate whether it controls an entity. Key areas of that evaluation include:

•Determining whether an entity is a VIE (see Note 2 – Variable Interest Entities);

•Determining whether Williams is the primary beneficiary of a VIE, including evaluating which activities of a VIE most significantly impact its economic performance and the degree of power that Williams and its related parties have over those activities through its variable interests;

•Identifying events that require reconsideration of whether an entity is a VIE and continuously evaluating whether Williams is a VIE’s primary beneficiary;

•Evaluating whether other owners in entities that are not VIEs are able to effectively participate in significant decisions that would be expected to be made in the ordinary course of business such that Williams does not have the power to control such entities.

Williams applies the equity method of accounting to investments over which it exercises significant influence but does not control. Distributions received from equity-method investees are presented in the Consolidated Statement of Cash Flows according to the nature of the distributions approach, which classifies distributions

received from equity-method investees as either returns on investment (cash inflows from operating activities) or returns of investment (cash inflows from investing activities) based on the nature of the activities of the equity-method investee that generated the distribution.

Use of estimates [Policy Text Block]

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying combined notes. Actual results could differ from those estimates.

Significant estimates and assumptions may include:

•Impairment assessments of investments, property, plant, and equipment, and intangible assets;

•Litigation-related contingencies;

•Environmental remediation obligations;

•Depreciation and amortization of long-lived assets, which are comprised of property, plant, and equipment, and intangible assets;

•Depreciation and/or amortization of equity-method investment basis differences;

•Asset retirement obligations (AROs);

•Measurement of fair value of commodity derivatives;

•Pension and postretirement valuation variables;

•Measurement of regulatory assets and liabilities;

•Measurement of deferred income tax assets and liabilities, including assumptions related to the realization of deferred income tax assets;

•Revenue recognition, including estimates utilized in recognition of deferred revenue;

•Purchase price accounting.

These estimates are discussed further throughout these combined notes.

Regulatory accounting [Policy Text Block]

Regulatory Accounting

Transco, NWP, and MountainWest are regulated by the Federal Energy Regulatory Commission (FERC), and these regulated entities’ rates may also be negotiated with customers pursuant to the terms of tariffs and FERC policy. Therefore, management has determined that it is appropriate under Accounting Standards Codification (ASC) Topic 980, “Regulated Operations,” (ASC 980) that certain costs that would otherwise be charged to expense should be deferred as regulatory assets, based on the expected recovery from customers in future rates. Likewise, certain actual or anticipated credits that would otherwise reduce expense should be deferred as regulatory liabilities, based on the expected return to customers in future rates. Management’s expected recovery of deferred costs and return of deferred credits generally results from specific decisions by regulators granting such ratemaking treatment. Certain incurred costs and obligations are recorded as regulatory assets or liabilities if, based on regulatory orders or other available evidence, it is probable that the costs or obligations will be included in amounts allowable for recovery or refunded in future rates. Accounting for these operations that are regulated can differ from the accounting requirements for nonregulated operations. For example, for regulated operations, allowance for funds used during construction (AFUDC) represents the estimated cost of debt and equity funds applicable to utility plant in the process of construction and is capitalized as a cost of property, plant, and equipment because it constitutes an

actual cost of construction under established regulatory practices; nonregulated operations are only allowed to capitalize the cost of debt funds related to construction activities, while a component for equity is prohibited. Management has determined that for its regulated entities, it is appropriate to apply the accounting prescribed by ASC 980 and, accordingly, the accompanying financial statements include the effects of the types of transactions described above that result from regulatory accounting requirements (see Note 10 – Regulatory Assets and Liabilities).

The FERC has prescribed a formula to be used in computing separate allowances for borrowed and equity AFUDC. These allowances are recorded as follows:

Transco

	Year Ended December 31,
	2024		2023		2022
	(Millions)
Allowance for borrowed funds used during construction	$	17	$	14	$	5
Allowance for equity funds used during construction	71		63		23
Allowance for equity and borrowed funds used during construction (AFUDC)	$	88	$	77	$	28

NWP

	Year Ended December 31,
	2024		2023		2022
	(Millions)
Allowance for borrowed funds used during construction	$	2	$	1	$	1
Allowance for equity funds used during construction	8		3		2
Allowance for equity and borrowed funds used during construction (AFUDC)	$	10	$	4	$	3

Revenue recognition [Policy Text Block]

Revenue Recognition

Customers in Williams’ gas pipeline businesses, including Transco and NWP, are comprised of public utilities, municipalities, gas marketers and producers, intrastate pipelines, direct industrial users, and electrical power generators. Customers in Williams’ midstream businesses are comprised of oil and natural gas producer counterparties. Customers for Williams’ product sales are comprised of public utilities, gas marketers, and direct industrial users.

Service revenue contracts from Williams’ gas pipeline and midstream businesses, including Transco and NWP, contain a series of distinct services, with the majority of the contracts having a single performance obligation that is satisfied over time as the customer simultaneously receives and consumes the benefits provided. Most of the product sales contracts have a single performance obligation with revenue recognized at a point in time when the products have been sold and delivered to the customer.

Certain customers reimburse Williams for costs it incurs associated with construction of property, plant, and equipment utilized in its operations. For Williams’ rate-regulated gas pipeline businesses, including Transco and NWP, that apply ASC 980, Williams follows FERC guidelines with respect to reimbursement of construction costs. FERC tariffs only allow for cost reimbursement and are non-negotiable in nature; thus, in management’s judgment, the construction activities do not represent an ongoing major and central operation of the gas pipeline businesses and are not within the scope of ASC Topic 606, “Revenue from Contracts with Customers”. Accordingly, cost reimbursements are treated as a reduction to the cost of the constructed asset. For the midstream businesses, reimbursement and service contracts with customers are viewed together as providing the same commercial objective, as Williams has the ability to negotiate the mix of consideration between reimbursements and amounts

billed over time. Accordingly, Williams generally recognizes reimbursements of construction costs from customers on a gross basis as a contract liability separate from the associated costs included within property, plant, and equipment. The contract liability is recognized into service revenues as the underlying performance obligations are satisfied.

Service Revenues

Gas pipeline businesses

Revenues from the regulated interstate natural gas pipeline businesses, including Transco and NWP, which are subject to regulation by certain state and federal authorities, including the FERC, include both firm and interruptible transportation and storage contracts. Firm transportation and storage agreements provide for a daily or monthly reservation charge based on the pipeline or storage capacity reserved, and a commodity charge based on the volume of natural gas delivered/stored, each at rates specified in the FERC tariffs or based on negotiated contractual rates, with contract terms that are generally long-term in nature. Most of the long-term contracts contain an evergreen provision, which allows the contracts to be extended for periods primarily up to one year in length an indefinite number of times following the specified contract term and until terminated generally by either party. Interruptible transportation and storage agreements provide for a volumetric charge based on actual commodity transportation or storage utilized in the period in which those services are provided, and the contracts are generally limited to one-month periods or less. The related performance obligations include the following:

•Firm transportation or storage under firm transportation and storage contracts—an integrated package of services typically constituting a single performance obligation, which includes standing ready to provide such services and receiving, transporting or storing (as applicable), and redelivering commodities;

•Interruptible transportation or storage under interruptible transportation and storage contracts—an integrated package of services typically constituting a single performance obligation once scheduled, which includes receiving, transporting or storing (as applicable), and redelivering commodities.

In situations where, in management’s judgment, it considers the integrated package of services as a single performance obligation, which represents a majority of its interstate natural gas pipeline contracts with customers, management does not consider there to be multiple performance obligations because the nature of the overall promise in the contract is to stand ready (with regard to firm transportation and storage contracts), receive, transport or store, and redeliver natural gas to the customer; therefore, revenue is recognized over time upon satisfaction of the daily stand ready performance obligation.

Revenues are recognized for reservation charges over the performance obligation period, which is the contract term, regardless of the volume of natural gas that is transported or stored. Revenues for commodity charges from both firm and interruptible transportation services and storage services are recognized when natural gas is delivered at the agreed upon delivery point or when natural gas is injected or withdrawn from the storage facility because they specifically relate to efforts to provide these distinct services. Generally, reservation charges and commodity charges in the interstate natural gas pipeline businesses are recognized as revenue in the same period they are invoiced to its customers. As a result of the ratemaking process, certain amounts collected may be subject to refund upon the issuance of final orders by the FERC in pending rate proceedings. Management uses judgment to record estimates of rate refund liabilities considering its and other third-party regulatory proceedings, advice of counsel, and other risks. As of December 31, 2024 and 2023, there were no such rate refund liabilities for Transco and NWP.

Midstream businesses

Revenues from the nonregulated gathering, processing, transportation, and storage midstream businesses include contracts for natural gas gathering, processing, treating, compression, transportation, and other related services with contract terms that are generally long-term in nature and may extend up to the production life of the associated reservoir. Additionally, the midstream businesses generate revenues from fees charged for storing customers’ natural gas and NGLs, generally under prepaid contracted storage capacity contracts. In situations where, in management’s judgment, it provides an integrated package of services combined into a single performance obligation, which represents a majority of this class of contracts with customers, Williams does not consider there to be multiple performance obligations because the nature of the overall promise in the contract is to provide gathering, processing, transportation, storage, and related services resulting in the delivery, or redelivery in the context of storage services, of pipeline-quality natural gas and NGLs to the customer. As such, revenue is recognized at the daily completion of the integrated package of services as the integrated package represents a single performance obligation. Additionally, certain contracts in the midstream businesses contain fixed or upfront payment terms that result in the deferral of revenues until such services have been performed or such capacity has been made available.

Williams also earns revenues from offshore crude oil and natural gas gathering and transportation and offshore production handling. These services represent an integrated package of services and are considered a single distinct performance obligation for which Williams recognizes revenues as the services are provided to the customer.

Williams generally earns a contractually stated fee per unit for the volume of product transported, gathered, processed, or stored. The rate is generally fixed; however, certain contracts contain variable rates that are subject to change based on commodity prices, levels of throughput, or an annual adjustment based on a formulaic cost-of-service calculation. In addition, Williams has contracts with contractually stated fees that decline over the contract term, such as declines based on the passage of time periods or achievement of cumulative throughput amounts. The excess of consideration received over revenue recognized results in the deferral of those amounts until future periods based on a units of production or straight-line methodology as these methods appropriately match the consumption of services provided to the customer. The units of production methodology requires the use of production estimates that are uncertain and the use of judgment when developing estimates of future production volumes, thus impacting the rate of revenue recognition. Production estimates are monitored as circumstances and events warrant. Certain of Williams’ gas gathering and processing agreements have minimum volume commitments (MVC). If a customer under such an agreement fails to meet its MVC for a specified period (thus not exercising all the contractual rights to gathering and processing services within the specified period, herein referred to as “breakage”), it is obligated to pay a contractually determined fee based upon the shortfall between the actual gathered or processed volumes and the MVC for the period contained in the contract. When Williams concludes, based on management’s judgment, it is probable that the customer will not exercise all or a portion of its remaining rights, Williams recognizes revenue associated with such breakage amount in proportion to the pattern of exercised rights within the respective MVC period.

Under keep-whole and percent-of-liquids processing contracts, Williams receives commodity consideration in the form of NGLs and takes title to the NGLs at the tailgate of the plant. Williams recognizes such commodity consideration as service revenue based on the market value of the NGLs retained at the time the processing is provided. The current market value, as opposed to the market value at the contract inception date, is used due to a combination of factors, including the fact that the volume, mix, and market price of NGL consideration to be received is unknown at the time of contract execution and is not specified in Williams’ contracts with customers. Additionally, product sales revenue (discussed below) is recognized upon the sale of the NGLs to a third party based on the sales price at the time of sale. As a result, revenue is recognized in the Consolidated Statement of Income both at the time the processing service is provided in Service revenues – commodity consideration and at the time the NGLs retained as part of the processing service are sold in Product

sales. The recognition of revenue related to commodity consideration has the impact of increasing the book value of NGL inventory, resulting in higher cost of goods sold at the time of sale.

Product Sales

In the course of providing transportation services to customers of the gas pipeline businesses, including Transco, and gathering and processing services to customers of the midstream businesses, different quantities of natural gas may be received from customers than the quantities delivered on behalf of those customers. The resulting imbalances are primarily settled monthly through the purchase or sale of natural gas with each customer under terms provided for in FERC tariffs or gathering and processing agreements, respectively. Revenue is recognized for Transco from the sale of natural gas upon settlement of imbalances (see Gas Imbalances below).

In certain instances, Williams purchases NGLs, crude oil, and natural gas from its oil and natural gas producer customers which Williams remarkets. In addition, Williams retains NGLs as consideration in certain processing arrangements, as discussed above in the Service Revenues - Midstream businesses section. Williams also markets natural gas and NGLs from the production at its upstream properties. Williams recognizes revenue from the sale of these commodities when the products have been sold and delivered. Williams’ product sales contracts are primarily short-term contracts based on prevailing market rates at the time of the transaction.

Williams purchases natural gas for storage when the current market price paid to buy and transport natural gas plus the cost to store and finance the natural gas is less than an estimated, forward market price that can be received in the future, resulting in positive net product sales. Commodity-based exchange-traded futures contracts and over-the-counter (OTC) contracts are used to sell natural gas at that future price to substantially protect the natural gas revenues that will ultimately be realized when the stored natural gas is sold. Additionally, Williams enters into transactions to secure transportation capacity between delivery points in order to serve its customers and various markets.

The physical purchase, transportation, storage, and sale of natural gas associated with these natural gas purchases are accounted for on a weighted-average cost or accrual basis, as appropriate, unlike the fair value basis utilized for the commodity derivatives used to mitigate the natural gas price risk associated with the storage and transportation portfolio. Monthly demand charges are incurred for contracted storage and transportation capacity and payments associated with asset management agreements and these demand charges and payments are recognized in the Consolidated Statement of Income in the period they are incurred.

As Williams is acting as an agent for its natural gas marketing customers and engages in energy trading activities, its natural gas marketing revenues are presented net of the related costs of those activities.

Contract Assets

Williams

Contract assets in the Consolidated Balance Sheet primarily consist of revenue recognized under contracts containing MVC features whereby management has concluded it is probable there will be a short-fall payment at the end of the current MVC period, which typically follows the calendar year, and that a significant reversal of revenue recognized currently for the future MVC payment will not occur. As a result, Williams’ contract assets related to its future MVC payments are generally expected to be collected within the next 12 months and are included within Other current assets and deferred charges in the Consolidated Balance Sheet until such time as the MVC short-fall payments are invoiced to the customer.

Transco and NWP

Transco’s contract assets primarily result from the modification of an existing contract resulting in increased rates. NWP’s contract assets consist of discounts provided to customers in the beginning of the contract term that are recognized on a straight-line basis over the entire contract term resulting in revenue

recognition occurring prior to actual billings. Current and noncurrent contract assets are included within Other current assets and deferred charges and Deferred charges and other, respectively, in the Balance Sheets.

Contract Liabilities

Williams

Contract liabilities in the Consolidated Balance Sheet consist of advance payments primarily from midstream business customers which include construction reimbursements, prepayments, and other billings and transactions for which future services are to be provided under the contract. These amounts are deferred until recognized in revenue when the associated performance obligation has been satisfied, which is primarily based on a units of production methodology over the remaining contractual service periods, and are classified as current or noncurrent according to when such amounts are expected to be recognized. Current and noncurrent contract liabilities are included within Other current liabilities and Regulatory liabilities, deferred income, and other, respectively, in the Consolidated Balance Sheet.

Contracts requiring advance payments and the recognition of contract liabilities are evaluated to determine whether the advance payments provide Williams with a significant financing benefit. This determination is based on the combined effect of the expected length of time between when Williams transfers the promised good or service to the customer, when the customer pays for those goods or services, and the prevailing interest rates. Williams has assessed its contracts for significant financing components and determined, in management’s judgment, that one group of contracts entered into in contemplation of one another for certain capital reimbursements contains a significant financing component. As a result, Williams recognizes noncash interest expense based on the effective interest method and revenue (noncash) is recognized when the underlying asset is placed into service utilizing a units of production or straight-line methodology over the life of the corresponding customer contract.

Transco and NWP

Transco’s contract liabilities consist of advance payments from customers, which include prepayments, and other billings for which future services are to be provided under the contract, and NWP’s contract liabilities consist of a fixed rate facility charge billed to customers with a declining rate structure in its tariffs. Transco assessed its contracts and determined none contain a significant financing component. These liabilities are classified as current or noncurrent according to when such amounts are expected to be recognized. Current and noncurrent contract liabilities are included within Other current liabilities and Deferred charges and other, respectively, in the Balance Sheets

Derivative instruments and hedging activities [Policy Text Block]

Commodity Derivative Instruments and Hedging Activities

Williams is exposed to commodity price risk and utilizes derivatives to manage a portion of its commodity price risk. These instruments consist primarily of swaps, futures, and forward contracts involving short- and long-term purchases and sales of energy commodities. Williams purchases natural gas for storage when the current market price paid to buy and transport natural gas plus the cost to store and finance the natural gas is less than an estimated, forward market price that can be received in the future. Additionally, Williams enters into transactions to secure transportation capacity between delivery points in order to serve its customers and various markets. Commodity-based exchange-traded futures contracts and OTC contracts are used to capture the price differential or spread between the locations served by the capacity in order to substantially protect the natural gas revenues that will ultimately be realized when the physical flow of natural gas between receipt and delivery points occurs. Some commodity derivative contracts require physical delivery as opposed to financial settlement, and this type of derivative is both common and prevalent within the natural gas marketing operations. These contracts generally meet the definition of derivatives and are typically not designated as hedges for accounting purposes. When a commodity derivative contract is settled physically, any cumulative unrealized gain or loss is reversed, and the contract price is recognized in the respective line item in the Consolidated Statement of Income representing the

actual price of the underlying goods being delivered. As of December 31, 2024 and 2023, Williams is not applying hedge accounting to any commodity derivative instruments.

Unrealized gains and losses from physically settled commodity derivative contracts for commodity sales transactions are recognized in Net gain (loss) from commodity derivatives in the Consolidated Statement of Income. Realized and unrealized gains and losses from non-designated commodity derivative contracts for commodity sales transactions that are financially settled are reported in Net gain (loss) from commodity derivatives in the Consolidated Statement of Income. Net gains and losses from derivatives for shrink gas purchases for processing plants are reported in Net processing commodity expenses in the Consolidated Statement of Income.

Williams experiences significant earnings volatility from the fair value accounting required for the derivatives used to hedge a portion of the economic value of the underlying transportation and storage portfolio as well as upstream related production. However, the unrealized fair value measurement gains and losses are generally offset by valuation changes in the economic value of the underlying production or transportation and storage contracts, which is not recognized until the underlying transaction occurs. (See Note 17 – Commodity Derivatives.)

Williams reports the fair value of derivatives, except those for which the normal purchases and normal sales exception has been elected, in Derivative assets; Regulatory assets, deferred charges, and other; Derivative liabilities; or Regulatory liabilities, deferred income, and other in the Consolidated Balance Sheet. These amounts are presented on a net basis and reflect the netting of asset and liability positions permitted under the terms of master netting arrangements and cash held on deposit in margin accounts that Williams has received or remitted to collateralize certain derivative positions. Williams determines the current and noncurrent classification based on the timing of expected future cash flows of individual trades.

The accounting for the changes in fair value of a commodity derivative can be summarized as follows:

Derivative Treatment	Accounting Method
Normal purchases and normal sales exception	Accrual accounting
All other derivatives	Mark-to-market accounting

Williams may elect the normal purchases and normal sales exception for certain short- and long-term purchases and sales of physical energy commodities. Under accrual accounting, any change in the fair value of these derivatives is not reflected in the Consolidated Balance Sheet after the initial election of the exception.

Interest capitalized [Policy Text Block]

Interest Capitalized

For its non-regulated companies, Williams capitalizes interest on its debt using the weighted-average interest rate on debt excluding debt issued by Transco, NWP, and MountainWest. This is included in Interest expense in Williams’ Consolidated Statement of Income.

For Williams’ regulated interstate natural gas pipelines, including Transco, NWP, and MountainWest, interest is capitalized from its borrowed funds and from internally generated funds (equity AFUDC) (see Regulatory Accounting). The former is included in Interest expense and the latter is included in Other income (expense) – net below Operating income (loss) in Williams’ Consolidated Statement of Income and Allowance for equity and borrowed funds used during construction (AFUDC) in Transco and NWP’s Statement of Net Income (see Note 9 – Property, Plant, and Equipment).

Income taxes [Policy Text Block]

Income Taxes

Williams includes the operations of its domestic corporate subsidiaries and income from its subsidiary partnerships, as well as income from Transco and NWP which are treated as pass-through entities for state and local income tax purposes, in its consolidated federal income tax return and also files tax returns in various foreign and state jurisdictions as required. Deferred income taxes are computed using the liability method and are provided on

all temporary differences between the financial basis and the tax basis of its assets and liabilities. Management’s judgment and income tax assumptions are used to determine the levels, if any, of valuation allowances associated with deferred tax assets.

Earnings (loss) per common share [Policy Text Block]

Earnings (Loss) Per Common Share

Williams’ Basic earnings (loss) per common share in the Consolidated Statement of Income is based on the sum of the weighted-average number of common shares outstanding and vested restricted stock units. Diluted earnings (loss) per common share in the Consolidated Statement of Income primarily includes any dilutive effect of nonvested restricted stock units and stock options. Diluted earnings (loss) per common share may also include any dilutive effect of Williams’ preferred stock. Diluted earnings (loss) per common share is calculated using the treasury-stock method.

Cash and cash equivalents [Policy Text Block]

Cash and Cash Equivalents

Cash and cash equivalents in the Consolidated Balance Sheet consist of highly liquid investments with original maturities of three months or less when acquired.

Accounts receivable [Policy Text Block]

Accounts Receivable

Accounts receivable are carried on a gross basis, with no discounting, less an allowance for doubtful accounts. Management estimates the allowance for doubtful accounts, considering current expected credit losses using a forward-looking “expected loss” model, the financial condition of its customers, and the age of past due accounts. The majority of trade receivable balances are due within 30 days. Management monitors the credit quality of its counterparties through review of collection trends, credit ratings, and other analyses, such as bankruptcy monitoring. Williams’ financial assets from its natural gas transmission business, natural gas storage business, gathering, processing and transportation business, marketing business, and upstream operations, as applicable, are segregated into separate pools for evaluation due to different counterparty risks inherent in each business, with Transco’s and NWP’s financial assets each evaluated as one pool. Changes in counterparty risk factors could lead to reassessment of the composition of financial assets as one pool, separate pools, or the need for additional pools. Management calculates its allowance for credit losses incorporating an aging method. In estimating its expected credit losses, management utilizes historical loss rates over many years, which for Williams includes periods of both high and low commodity prices. Transco’s and NWP’s expected credit loss estimates considered both internal and external forward-looking commodity price expectations, as well as counterparty credit ratings, and factors impacting near-term liquidity.

Commodity prices could have a significant impact on a portion of Williams’ gathering and processing and upstream counterparties’ financial health and ability to satisfy current obligations. Williams’ expected credit loss estimate considers both internal and external forward-looking commodity price expectations, as well as counterparty credit ratings, and factors impacting near-term liquidity. In addition, Williams’ expected credit loss estimate considers potential contractual, physical, and commercial protections and outcomes in the case of a counterparty bankruptcy. The physical location and nature of Williams’ services help to mitigate collectability concerns of its gathering and processing producer customers. Williams’ gathering lines in many cases are physically connected to the customers’ wellheads and pads, and there may not be alternative gathering lines nearby. The construction of gathering systems is capital intensive and it would be costly for others to replicate, especially considering the depletion to date of the associated reserves. As a result, Williams plays a critical role in getting customers’ production from the wellhead to a marketable condition and location. This tends to reduce collectability risk as Williams’ services enable producers to generate operating cash flows. Commodity price movements generally do not impact the majority of Williams’ natural gas transmission businesses customers’ financial condition.

Williams also provides marketing and risk management services to retail and wholesale gas marketers, utility companies, upstream producers, and industrial customers. These counterparties utilize netting agreements that enable Williams to net receivables and payables by counterparty upon settlement. Williams also nets across product lines and against cash collateral received to collateralize receivable positions, provided the netting and cash

collateral agreements include such provisions. While the amounts due from, or owed to, Williams’ counterparties are settled net, these amounts are recorded on a gross basis in the Consolidated Balance Sheet as accounts receivable and accounts payable.

Extended payment terms are not offered and payments are typically received within one month. Receivables are considered past due if full payment is not received by the contractual due date. Past due accounts are generally written off against the allowance for doubtful accounts only after all collection attempts have been exhausted. Neither Williams, Transco, nor NWP have a material amount of significantly aged receivables at December 31, 2024 or 2023.

Oil and Gas, Gas-Balancing Arrangement

Gas Imbalances

Transco

Transco transports gas on various pipeline systems which may deliver different quantities of gas on behalf of Transco than the quantities of gas received from Transco. These transactions result in gas transportation and exchange imbalance receivables and payables which are recovered or repaid in cash or through the receipt or delivery of gas in the future and are recorded in the accompanying Balance Sheet. Revenues received from the cash-out of transportation imbalances in excess of costs incurred are deferred and offset by the deferral of costs incurred in excess of revenues received. At the end of each annual August through July reporting period, if the cumulative revenues received exceed the costs incurred, the over recovered amounts are applied to any prior under recovery balance or refunded. If the cumulative revenues received are less than the costs incurred, the net under recovered amounts are carried forward and offset against any future net over recoveries that may occur in a subsequent annual reporting period. These deferred recoveries are recognized as Regulatory assets in Transco’s Balance Sheet (see Note 10 – Regulatory Assets and Liabilities).

The settlement of imbalances requires agreement between the pipelines and shippers as to allocations of volumes to specific transportation contracts and timing of delivery of gas based on operational conditions. These imbalances are classified as Other current assets and deferred charges and Other current liabilities in Transco’s Balance Sheet (see Note 10 – Regulatory Assets and Liabilities). Transco utilizes the average cost method of accounting for gas imbalances.

NWP

In the course of providing transportation services to customers, NWP may receive different quantities of natural gas from customers than the quantities delivered on behalf of those customers or consumed in fuel to operate NWP’s system. The resulting customer imbalances are typically settled through the receipt or delivery of gas in the future based on the timelines outlined in NWP’s tariff, whereas the over/under recovery of fuel is cleared up through NWP’s semi-annual fuel tracker. Customer imbalances to be repaid or recovered in-kind are recorded as Other current assets and deferred charges or Other current liabilities in NWP’s Balance Sheet. The under recovery of fuel is recorded as Regulatory assets and the over recovery is recorded in Regulatory liabilities in NWP’s Balance Sheet (see Note 10 – Regulatory Assets and Liabilities). These imbalances are valued at published spot rates.

Inventories [Policy Text Block]

Inventories

Inventories in Williams’ Consolidated Balance Sheet primarily consist of NGLs, materials and supplies, and natural gas in underground storage and are primarily stated at the lower of cost or net realizable value. The cost of inventories are primarily determined using the average cost method. Inventories in Transco’s and NWP’s Balance Sheets primarily consist of materials and supplies and natural gas in underground storage.

Environmental Costs, Policy

Transco and NWP Environmental Matters

Transco and NWP are subject to federal, state, and local environmental laws and regulations. Environmental expenditures are expensed or capitalized depending on the economic benefit and potential for rate recovery. These

entities believe that expenditures required to meet applicable environmental laws and regulations are prudently incurred in the ordinary course of business and such expenditures would be permitted to be recovered through rates with limited exceptions.

In accordance with the Climate Commitment Act of the state of Washington, which established a market-based cap-and-invest program, NWP is required to obtain emission allowances for the carbon emissions from nine of NWP’s thirteen compressor stations within the state of Washington whose annual carbon emissions exceed 25,000 metric tons of carbon dioxide equivalent at least once since 2015. NWP records the purchased emission allowances at cost and the associated accumulated interest to a regulatory asset. The difference between the allowances held and the allowances required based on actual emissions for the period are measured using an estimate based on NWP’s most recent cost of allowances and accrued to a current liability and to a regulatory asset. NWP’s Petition for Approval of Pre-Filing Stipulation and Settlement Agreement (Settlement) in Docket No. RP22-1155, which FERC approved in 2022, allows NWP to recover the costs of purchasing allowances under the program in its next rate case (see Note 18 – Contingencies and Commitments).

Property, plant, and equipment [Policy Text Block]

Property, Plant, and Equipment

Property, plant, and equipment is initially recorded at cost. The carrying value of these assets is based on estimates, assumptions, and judgments relative to capitalized costs, useful lives, and salvage values. For the Transco, NWP, and MountainWest interstate natural gas pipelines, these estimates, assumptions and judgments reflect FERC regulations, as well as historical experience and expectations regarding future industry conditions and operations. The FERC identifies installation, construction and replacement costs that are to be capitalized. All other costs are expensed as incurred.

As regulated entities, Transco, NWP and MountainWest provide for depreciation primarily under the composite (group) method using straight-line FERC-prescribed rates. Under this method, assets with similar lives and characteristics are grouped and depreciated as one asset. These regulated entities’ depreciation rates are subject to change each time these regulated entities file a general rate case with the FERC. Included in Transco’s and NWP’s depreciation rates is a negative salvage component (net cost of removal) that Transco and NWP currently collect in rates that is recorded as a regulatory liability in the Balance Sheets (see Note 10 – Regulatory Assets and Liabilities).

Depreciation for Williams’ nonregulated entities is provided primarily on the straight-line method over estimated useful lives.

Williams follows the successful efforts method of accounting for its upstream properties. Its oil and gas producing property costs are depreciated using the units of production method.

Gains or losses from the ordinary sale or retirement of property, plant, and equipment for the Transco, NWP, and MountainWest interstate natural gas pipelines are credited or charged to accumulated depreciation; certain other gains or losses are recorded in Other (income) expense – net included in Operating income (loss) in the statements of income. Gains or losses from the ordinary sale or retirement of property, plant, and equipment for Williams’ nonregulated assets are primarily recorded in Other (income) expense – net included in Operating income (loss) in the Consolidated Statement of Income.

Ordinary maintenance and repair costs are generally expensed as incurred. Costs of major renewals and replacements are capitalized as property, plant, and equipment.

Williams records a liability and increases the basis in the underlying asset for the present value of each expected future ARO at the time the liability is initially incurred, typically when the asset is acquired or constructed. For Williams’ upstream properties, the ARO is recorded based on Williams’ working interest in the underlying properties. As regulated entities, Transco’s and NWP’s depreciation expense and accretion expense are offset and recorded as a regulatory asset as the regulated entities expect to recover these accretion expenses in future rates and measure changes in the liability due to passage of time by applying an interest rate to the liability balance. This step

is recognized as an increase in the carrying amount of the liability included in Operating and maintenance expenses and as a corresponding accretion expense included in Other (income) expense - net in the Consolidated Statement of Income. The regulatory asset is amortized commensurate with these regulated entities’ collection of those costs in rates.

Measurements of AROs include, as a component of future expected costs, an estimate of the price that a third party would demand, and could expect to receive, for bearing the uncertainties inherent in the obligations, sometimes referred to as a market-risk premium.

Goodwill [Policy Text Block]

Goodwill

Goodwill included within Intangible assets – net of accumulated amortization in Williams’ Consolidated Balance Sheet, as of December 31, 2024, represents the excess of the consideration, plus the fair value of any noncontrolling interest or any previously held equity interest, over the fair value of the net assets acquired. It is not subject to amortization but is evaluated annually as of October 1 for impairment or more frequently if impairment indicators are present that would indicate it is more likely than not that the fair value of the reporting unit is less than its carrying amount. Management first performs a qualitative assessment to test goodwill on a reporting unit by reporting unit basis to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, management compares its estimate of fair value of the reporting unit to its carrying amount, including goodwill. Judgments and assumptions are inherent in management’s estimates of fair value.

Intangible assets [Policy Text Block]

Other Identifiable Intangible Assets

Williams’ other identifiable intangible assets included within Intangible assets – net of accumulated amortization in the Consolidated Balance Sheet are primarily related to gas gathering, processing, and fractionation customer relationships. Williams’ other identifiable intangible assets are generally amortized on a straight-line basis over the period in which these assets contribute to its cash flows. Williams evaluates these assets for changes in the expected remaining useful lives and reflects any changes prospectively through amortization over the revised remaining useful life.

Impairment of property, plant, and equipment, intangible assets, and investments [Policy Text Block]

Impairment of Property, Plant, and Equipment, Intangible Assets, and Investments

Management evaluates property, plant, and equipment and intangible assets for impairment when, in its judgment, events or circumstances, including probable abandonment, indicate that the carrying value of such assets may not be recoverable. When an indicator of impairment has occurred, management compares its estimate of undiscounted future cash flows attributable to the assets to the carrying value of the assets to determine whether an impairment has occurred and may apply a probability-weighted approach to consider the likelihood of different cash flow assumptions and possible outcomes, including selling the assets in the near term or holding them for the asset’s remaining estimated useful life. If an impairment of the carrying value has occurred, management determines the amount of the impairment to be recognized in the financial statements by estimating the fair value of the assets and recording a loss for the amount that the carrying value exceeds the estimated fair value. This evaluation is performed at the lowest level for which separately identifiable cash flows exist.

For assets identified to be disposed of in the future and considered held for sale, management compares the carrying value to the estimated fair value less the cost to sell to determine if recognition of an impairment is required. Until the assets are disposed of, the estimated fair value, which includes estimated cash flows from operations until the assumed date of sale, is recalculated when related events or circumstances change.

Williams’ investments are evaluated for impairment when, in management’s judgment, events or circumstances indicate that the carrying value of such investments may have experienced an other-than-temporary decline in value. When evidence of loss in value has occurred, management compares its estimate of fair value of the investment to the carrying value of the investment to determine whether an impairment has occurred. If the estimated fair value is

less than the carrying value and management considers the decline in value to be other-than-temporary, the excess of the carrying value over the fair value is recognized in the financial statements as an impairment charge.

Judgment and assumptions are inherent in the estimate of undiscounted future cash flows and an asset’s or investment’s fair value. Additionally, judgment is used to determine the probability of sale with respect to assets considered for disposal.

Equity-method investment basis differences [Policy Text Block]

Equity-Method Investment Basis Differences

Differences between the carrying value of Williams’ equity-method investments and the underlying equity in the net assets of investees are accounted for as if the investees were consolidated subsidiaries. Equity earnings (losses) in the Consolidated Statement of Income includes Williams’ allocable share of net income (loss) of investees adjusted for any depreciation and amortization, as applicable, associated with basis differences.

Leases [Policy Text Block]

Leases

Williams, Transco, and NWP recognize operating lease liabilities based on the present value of the future lease payments and have elected to combine lease and nonlease components for all classes of leased assets in the calculation of the lease liability and the offsetting right-of-use asset in the respective Balance Sheets.

Williams’, Transco’s, and NWP’s lease agreements require both fixed and variable periodic payments, with initial terms typically ranging from one year to 20 years for Williams and up to 30 years for Transco and NWP. Payment provisions in certain lease agreements contain escalation factors which may be based on stated rates or a change in a published index at a future time. The amount by which a lease escalates based on the change in a published index, which is not known at lease commencement, is considered a variable payment and is not included in the present value of the future lease payments, which only includes those that are stated or can be calculated based on the lease agreement at lease commencement. In addition to the noncancellable periods, many of Williams’ lease agreements provide for one or more extensions of the lease agreement for periods ranging from one year in length to an indefinite number of times following the specified contract term. Other lease agreements provide for extension terms that allow Williams, Transco, and NWP to utilize the identified leased asset for an indefinite period of time so long as the asset continues to be utilized in its operations. In consideration of these renewal features, management assesses the term of the lease agreements, which includes using judgment in the determination of which renewal periods and termination provisions, when at its sole election, will be reasonably certain of being exercised. Periods after the initial term or extension terms that allow for either party to the lease to cancel the lease are not considered in the assessment of the lease term. Additionally, management has elected to exclude leases with an original term of one year or less, including renewal periods, from the calculation of the lease liability and the offsetting right-of-use asset.

Judgment is used in determining the discount rate upon which the present value of the future lease payments is determined. This rate is based on a collateralized interest rate corresponding to the term of the lease agreement using company, industry, and market information available.

When permitted under its lease agreements, Williams may sublease certain unused office space for fixed periods that could extend up to the length of the original lease agreement.

Pension and other postretirement benefits [Policy Text Block]

Pension and Other Postretirement Benefits

The funded status of each of the pension and other postretirement benefit plans is recognized separately in Williams’ Consolidated Balance Sheet as either an asset or liability. The plans’ benefit obligations and net periodic benefit costs (credits) are actuarially determined and impacted by various assumptions and estimates.

The discount rates are determined separately for each of Williams’ pension and other postretirement benefit plans based on an approach specific to Williams’ plans. The year-end discount rates are determined considering a

yield curve comprised of high-quality corporate bonds and the timing of the expected benefit cash flows of each plan.

The expected long-term rates of return on plan assets are determined by combining a review of the historical returns within the portfolio, the investment strategy included in the plans’ investment policy statement, and capital market projections for the asset classes in which the portfolio is invested, as well as the weighting of each asset class.

Unrecognized actuarial gains and losses are deferred and recorded in AOCI or, for Transco and NWP, as a regulatory asset or liability, until amortized as a component of net periodic benefit cost (credit). The unrecognized net actuarial gains (losses) deferred in AOCI at December 31, 2024 and 2023 were $55 million and ($17) million, respectively. Unrecognized actuarial gains and losses in excess of 10 percent of the greater of the benefit obligation or the market-related value of plan assets are amortized over the participants’ average remaining future years of service, which is approximately 9 years for Williams’ pension plans and approximately 4 years for Williams’ other postretirement benefit plan.

The expected return on plan assets component of net periodic benefit cost (credit) is calculated using the market-related value of plan assets. For Williams’ pension plans, the market-related value of plan assets is equal to the fair value of plan assets adjusted to reflect the amortization of gains or losses associated with the difference between the expected and actual return on plan assets over a 5-year period. Additionally, the market-related value of assets may be no more than 110 percent or less than 90 percent of the fair value of plan assets at the beginning of the year. The market-related value of plan assets for Williams’ other postretirement benefit plan is equal to the unadjusted fair value of plan assets at the beginning of the year.

Contingent liabilities [Policy Text Block]

Contingent Liabilities

Liabilities for loss contingencies, including environmental matters, are recorded when management assesses that a loss is probable and the amount of the loss can be reasonably estimated. These liabilities are calculated based upon management’s assumptions and estimates with respect to the likelihood or amount of loss and upon advice of legal counsel, engineers, or other third parties regarding the probable outcomes of the matters. These calculations are made without consideration of any potential recovery from third parties. Insurance recoveries or reimbursements from others are recognized when realizable. Revisions to these liabilities are generally reflected in income when new or different facts or information become known or circumstances change that affect the previous assumptions or estimates.

Treasury stock [Policy Text Block]

Treasury Stock

Treasury stock purchases are accounted for under the cost method whereby the entire cost of the acquired stock is recorded as Treasury stock, at cost in Williams’ Consolidated Balance Sheet. Gains and losses on the subsequent reissuance of shares are credited or charged to Capital in excess of par value in the Consolidated Balance Sheet using the average cost method.

Cash Flows From Operating Activities

Cash Flows from Operating Activities

Williams, Transco, and NWP use the indirect method to report cash flows from operating activities, which requires adjustments to net income to reconcile to net cash flows provided by operating activities.

Cash flows from revolving credit facility and commercial paper program [Policy Text Block]

Cash Flows from Revolving Credit Facility and Commercial Paper Program

Proceeds and payments related to borrowings under Williams’ revolving credit facility are reflected in the financing activities in the Consolidated Statement of Cash Flows on a gross basis. Proceeds and payments related to borrowings under Williams’ commercial paper program are reflected in the financing activities in the Consolidated Statement of Cash Flows on a net basis, as the outstanding notes generally have maturity dates less than three months from the date of issuance. (See Note 13 – Debt and Banking Arrangements.)

New Accounting Pronouncements, Policy

Accounting Standards Issued But Not Yet Adopted

In December 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) 2023-09, Income Taxes: Improvements to Income Tax Disclosures, which requires disclosure of specific categories in the rate reconciliation and additional information for reconciling items that meet a quantitative threshold. This ASU is effective for fiscal years beginning after December 15, 2024, and early adoption is permitted. The adoption of ASU 2023-09 is not expected to have a material impact on the financial statements.

In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures, which requires public entities to disclose additional information in the notes to financial statements for certain types of expenses (including purchases of inventory, employee compensation, depreciation, amortization, and depletion) in commonly presented expense captions (such as cost of sales, selling, general & administrative expenses, and research and development). The amendments are effective for annual periods beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027 with early adoption permitted. The impact of this standard is currently being evaluated.