NORTHWEST PIPELINE LLC

Williams’ strategy is to provide a large-scale, reliable, and clean energy infrastructure designed to maximize the opportunities created by the vast supply of natural gas and natural gas products that exists in the United States. Williams accomplishes this by connecting the growing demand for cleaner fuels and feedstocks with our major positions in the premier natural gas and natural gas products supply basins. Williams continues to maintain a strong commitment to safety, environmental stewardship including seeking opportunities for renewable energy ventures, operational excellence, and customer satisfaction. Williams believes that accomplishing these goals will position it to deliver safe, reliable, clean energy services to its customers and an attractive return to shareholders. Williams’ business plan for 2026 includes a continued focus on earnings and cash flow growth.

In 2026, Williams’ operating results are expected to benefit from the continued growth in the Transmission, Power & Gulf segment, primarily reflecting the impacts of the Socrates Power Innovation project, as well as numerous expansion projects at Transco and the Gulf of America. Growth in 2026 will benefit from a full year of the Louisiana Energy Gateway expansion project as well as expected increases in Haynesville Shale volumes. Additionally, Williams expects higher gathering and processing results in the Northeast. These increases are partially offset by the divestiture of the South Mansfield upstream joint venture, and lower expected Eagle Ford results in our West segment related to minimum volume commitment reductions.

Williams seeks to maintain a strong financial position and liquidity, as well as manage a diversified portfolio of safe, clean, and reliable energy infrastructure assets that continue to serve key growth markets and supply basins in the United States. Williams’ growth capital and investment expenditures in 2026 are expected to range from $6.1 billion to $6.7 billion, excluding acquisitions and certain long-lead time equipment for power innovation projects which are backed by reimbursement from the customer if the equipment order is cancelled. Growth capital spending in 2026 primarily includes the Power Innovation projects, Transco expansions, all of which are fully contracted with firm transportation agreements, projects supporting growth in the Haynesville Shale basin, and projects supporting the Northeast G&P business. Williams is investing capital in the Louisiana LNG and Driftwood Pipeline projects, as well as the development of its Wamsutter upstream oil and gas properties. In addition to growth capital and investment expenditures, Williams also remains committed to projects that maintain its assets for safe and reliable operations, as well as projects that reduce emissions, and meet legal, regulatory, and/or contractual commitments. See Note 18 – Contingencies and Commitments for further discussion of Williams’ commitments.

Potential risks and obstacles that could impact the execution of Williams’ plan include:

•A global recession, which could result in downturns in financial markets and commodity prices, as well as impact demand for natural gas and related products;

•Opposition to, and regulations affecting, our infrastructure projects, including the risk of delay or denial in permits and approvals needed for our projects;

•Counterparty credit and performance risk;

•Unexpected significant increases in capital expenditures or delays in capital project execution, including increases from inflation or delays caused by supply chain disruptions;

•Unexpected changes in customer drilling and production activities, which could negatively impact gathering and processing volumes;

•Lower than anticipated demand for natural gas and natural gas products which could result in lower-than-expected volumes, energy commodity prices, and margins;

•General economic, financial markets, or industry downturns, including increased inflation, interest rates, or tariffs;

•Physical damages to facilities, including damage to offshore facilities by weather-related events;

•Other risks set forth under Part I, Item 1A. Risk Factors.

Expansion Projects

Williams’ ongoing major expansion projects include the following:

Gillis West

Transco plans to file a prior notice application with the FERC in 2026 for the project, which involves an expansion of Transco’s existing natural gas transmission system to provide incremental firm transportation capacity from receipt points in Louisiana to delivery points in Texas. Transco plans to place the project into service as early as the second quarter of 2026, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase capacity by 115 Mdth/d.

Southeast Supply Enhancement

In January 2026, Transco received approval from the FERC for the project, which involves an expansion of Transco’s existing natural gas transmission system to provide incremental firm transportation capacity from receipt points in Virginia to delivery points in Virginia, North Carolina, South Carolina, Georgia, and Alabama. Transco plans to place the project into service as early as the third quarter of 2027, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase capacity by 1,597 Mdth/d.

Northeast Supply Enhancement

In August 2025, the FERC issued an order granting Transco’s petition for reissuance of the certificate authorization for the project, which involves an expansion of Transco’s existing natural gas transmission system to provide incremental firm transportation capacity from Transco’s Compressor Station 195 in Pennsylvania to the Rockaway Delivery Lateral transfer point in New York. In October and November 2025, Transco’s applications for Clean Water Act and related permits with the states of Pennsylvania, New York and New Jersey were approved. In August 2025, Transco executed precedent agreements with customers subscribing to all of the capacity under the project. Transco plans to place the project into service as early as the fourth quarter of 2027, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase capacity by 400 Mdth⁄d.

Pine Prairie Phase IV Expansion

In August 2025, Williams filed a certificate application with the FERC for the project, which will involve an expansion of storage capacity and the injection and withdrawal capabilities of one of its existing storage facilities in the Gulf Coast region. Williams plans to place the project into service during the fourth quarter of 2028, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase working gas storage capacity by 10 Bcf.

Dalton Lateral II

Transco plans to file a certificate application for the project with the FERC in 2027. The project involves an expansion of Transco’s existing natural gas transmission system to provide incremental firm transportation capacity from Transco’s main line near existing Station 115 to an existing power plant in Georgia. Transco plans to place the project into service as early as the fourth quarter of 2029, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase capacity up to 460 Mdth/d.

Power Express

Transco plans to file an application with the FERC as early as the second quarter 2027 for the project, which involves an expansion of Transco’s existing natural gas transmission system to provide incremental firm transportation capacity in Virginia. Transco plans to place the project into service as early as the third quarter of 2030, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase capacity by 689 Mdth/d.

Naughton Coal-to-Gas Conversion

The project involves an expansion of NWP’s existing natural gas transmission system to provide year-round transportation capacity to a power plant in southwest Wyoming. NWP plans to place the project into service as early as the second quarter of 2026, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase capacity by 98 Mdth/d.

Ryckman Creek Loop

In January 2026, NWP received approval from the FERC for the project, which involves an expansion of NWP’s existing natural gas transmission system to provide incremental firm transportation capacity from a receipt point in northeast Oregon to multiple delivery points in southwest Wyoming. NWP plans to place the project into service as early as the fourth quarter of 2026. The project is expected to increase capacity by 50 Mdth/d.

Huntingdon Connector

NWP plans to file a prior notice application for the project with the FERC in the first quarter of 2026. The project involves an expansion of NWP’s existing natural gas transmission system that will provide year-round transportation capacity from the Sumas receipt point to various delivery points in Washington. NWP plans to place the project into service during the fourth quarter of 2026, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase capacity by 78 Mdth/d.

Wild Trail

In May 2025, NWP filed a certificate application with the FERC for the project, which involves an expansion of NWP’s existing natural gas transmission system that will provide year-round transportation capacity from the White River Hub receipt point in western Colorado to various delivery points in southwest Wyoming and southern Colorado. The Wild Trail project is fully subscribed by an affiliate of NWP. NWP plans to place the project into service during the fourth quarter of 2027, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase capacity by 83 Mdth/d.

Kelso-Beaver Reliability

In November 2025, NWP received approval from the FERC for the project. The Kelso-Beaver Reliability project on NWP’s existing natural gas transmission system will provide year-round transportation capacity to various receipt and delivery points in Oregon. NWP plans to place the project into service during the fourth quarter of 2028, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase capacity by 183 Mdth/d.

Power Innovation

Socrates

Williams has received approval from the Ohio Power Siting Board for the power generation facilities and is expecting final approval for the associated gas pipeline infrastructure in the first half of 2026. The Socrates project involves the construction of the Socrates North and South power generation facilities in New Albany, Ohio. Williams has agreed to provide committed power generation and associated gas pipeline infrastructure for the project, which is expected to provide a combined 400 megawatts of onsite power generation capacity to the customer. The project is backed by a 10 year, primarily fixed-price power purchase agreement, with an option for the customer to extend the term of the agreement. Williams plans to place the project into service in the third and fourth quarter of 2026, assuming timely receipt of permits.

Additional Projects

Williams has agreed to provide committed power generation and associated gas pipeline infrastructure for three additional Power Innovation projects, Apollo, Aquila and Socrates the Younger. The projects are backed by primarily fixed-price power purchase agreements, with options for the customer to extend the term of the agreements. The Apollo project, in Ohio, has a term of 12.5 years, and Williams expects the project to be placed into service in the second half of 2027. The Aquila project, in Utah, also has a term of 12.5 years, and Williams expects the project to be placed into service in the second half of 2027 and the first half of 2028. The Socrates the Younger project, in Ohio, has a term of 10 years, and Williams expects the project to be placed into service the second half of 2028. All expected in-service dates assume timely receipt of permits.

West

Dorne

Williams will construct and operate a greenfield treating and dehydration facility with a capacity of 400 MMcf/d. This project is expected to be placed into service in the third quarter of 2027.

Critical Accounting Estimates

Preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions. The nature of these estimates and assumptions is material due to the subjectivity and judgment necessary, or the susceptibility of such matters to change, and the impact of these on the financial condition or results of operations.

Regulatory Accounting

Williams’ regulated interstate natural gas pipelines, including Transco and NWP, are regulated by the FERC. Accounting Standards Codification (ASC) Topic 980, “Regulated Operations,” (ASC 980) provides 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 operations that are regulated and apply the provisions of ASC 980 can differ from the accounting requirements for nonregulated operations. Transactions that are recorded differently as a result of regulatory accounting requirements include the capitalization of an equity return component on regulated capital projects, capitalization of other project costs, retirements of general plant assets, levelized cost of service, employee-related benefits, environmental costs, negative salvage, asset retirement obligations (AROs), as well as other costs and taxes included in, or expected to be included in, future rates. Management has determined that for its rate-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. Management’s assessment of the probability of recovery or pass-through of regulatory assets and liabilities requires judgment and interpretation of laws and regulatory commission orders. If, for any reason, any of Williams’ regulated interstate natural gas pipelines, including Transco or NWP, ceases to meet the criteria for application of regulatory accounting treatment for all or part of its operations, the regulatory assets and liabilities related to those portions ceasing to meet such criteria would be eliminated from the respective balance sheet and included in the respective statement of income for the period in which the discontinuance of regulatory accounting treatment occurs and can be estimated, unless otherwise required to be recorded under other provisions of U.S. generally accepted accounting principles.

The aggregate amount of regulatory assets reflected on Williams’ Consolidated Balance Sheet was $698 million at December 31, 2025, of which Transco’s and NWP’s Balance Sheets reflected $394 million and $83 million, respectively. The aggregate amount of regulatory liabilities reflected on Williams’ Consolidated Balance Sheet was $1.3 billion at December 31, 2025, of which Transco’s and NWP’s Balance Sheets reflected $1.0 billion and $245 million, respectively. A summary of regulatory assets and liabilities is included in Note 10 – Regulatory Assets and Liabilities.