Southwest Airlines Co. (the "Company" or "Southwest") operates Southwest Airlines, a major domestic airline. The Consolidated Financial Statements include the accounts of the Company and its wholly owned subsidiaries. The accompanying Consolidated Financial Statements include the results of operations and cash flows for all periods presented and all significant inter-entity balances and transactions have been eliminated. The preparation of financial statements in conformity with generally accepted accounting principles in the United States ("GAAP") requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from these estimates.

In late December 2022, Winter Storm Elliott impacted a significant portion of the United States, leading to wide-scale operational disruptions for the Company. In attempting to recover from this weather event, the Company was challenged in its efforts to realign flight crews, flight schedules, and fleet for a period of days during this peak demand travel period. As a result, the Company canceled a significant number of flights between December 21 and December 29, before ultimately returning to a normal flight schedule on December 30, 2022. These canceled flights resulted in a significant reduction in Passenger revenues during this period and also created a deceleration in bookings, primarily isolated to January and February 2023. In addition, the Company incurred significant costs associated with this event and recorded these expenses during December 2022 and first quarter 2023, totaling approximately $390 million and $55 million, respectively, which are included in the accompanying Consolidated Statement of Income. These estimated items included reimbursements to Customers impacted by the cancellations for costs they incurred, the estimated value of Rapid Rewards points offered as a gesture of goodwill to Customers that are expected to be redeemed, and additional premium pay and additional compensation for Employees directly or indirectly impacted by the cancellations and recovery efforts. The financial impacts of the event to the Company also included lower fuel and oil and profitsharing expenses.

Based on the Company's wide-scale operational disruption, the Company could be subject to fines and/or penalties resulting from investigations by government agencies as well as litigation from Customers and Shareholders. On October 27, 2023, the Department of Transportation (the "DOT") notified the Company that it had determined the Company failed to provide adequate customer service assistance, prompt flight status notifications, and proper and prompt refunds and that the assessment of a civil penalty was warranted. During fourth quarter 2023, the Company accrued an expense of $107 million associated with a settlement reached with the DOT in December 2023 based on their investigation into the disruption.

Cash in excess of that necessary for operating requirements is invested in short-term, highly liquid, income-producing investments. Investments with original maturities of three months or less when purchased are classified as cash and cash equivalents, which primarily consist of certificates of deposit, money market funds, and investment grade commercial paper issued by major corporations and financial institutions. Cash and cash equivalents are stated at cost, which approximates fair value.

As of December 31, 2023 and 2022, $50 million and $106 million, respectively, in cash collateral deposits were held by the Company from its fuel hedge counterparties. As of December 31, 2023, the Company had no outstanding interest rate swap agreements and therefore no cash collateral deposits were provided by or held by the Company from interest rate hedge counterparties. Additionally, as of December 31, 2022, no cash collateral deposits were provided by or held by the Company based on its outstanding interest rate swap agreements. Cash collateral amounts provided or held associated with fuel and interest rate derivative instruments are not restricted in any way and earn interest income at an agreed upon rate that approximates the rates earned on short-term securities issued by the U.S. Government. Depending on the fair value of the Company’s fuel and interest rate derivative instruments, the amounts of collateral deposits held or provided at any point in time can fluctuate significantly. See Note 11 for further information on these collateral deposits and fuel derivative instruments.

Short-term investments consist of investments with original maturities of greater than three months but less than twelve months when purchased. These are primarily short-term securities issued by the U.S. Government and certificates of deposit issued by domestic banks. All of these investments are classified as available-for-sale securities and are stated at fair value, which approximates cost. For all short-term investments, at each reset period or upon reinvestment, the Company accounts for the transaction as Proceeds from sales of short-term and other investments for the security relinquished, and Purchases of short-term investments for the security purchased, in the accompanying Consolidated Statement of Cash Flows. Unrealized gains and losses, net of tax, if any, are recognized in Accumulated other comprehensive income (loss) ("AOCI") in the accompanying Consolidated Balance Sheet. Realized net gains and losses on specific investments, if any, are reflected in Interest income in the accompanying Consolidated Statement of Income. Both unrealized and realized gains and/or losses associated with investments were immaterial for all years presented.

Accounts and other receivables are initially recorded at cost and are evaluated for collectability in every period. They primarily consist of the amounts due from the Company's business partners and other suppliers, amounts due from credit card companies associated with sales of tickets for future travel, amounts due from business partners in the Company’s loyalty program, and tax receivables from overpayment or net operating losses that are allowed to be carried back to prior periods to claim refunds against prior taxes paid. See Note 16 for further information. The allowance for doubtful accounts was immaterial as of December 31, 2023 and 2022. In addition, the provision for doubtful accounts and write-offs for 2023, 2022, and 2021 were each immaterial.

Inventories primarily consist of aircraft fuel and flight equipment expendable parts, materials, and supplies. All of these items are carried at average cost, less an allowance for obsolescence. These items are generally charged to expense when issued for use. The reserve for obsolescence was immaterial as of December 31, 2023, and 2022. In addition, the Company’s provision for obsolescence and write-offs for 2023, 2022, and 2021 were each immaterial.

Property and equipment is stated at cost. Capital expenditures include payments made for aircraft, other flight equipment, purchase deposits related to future aircraft deliveries, airport and other facility construction projects, and ground and other property and equipment. Depreciation is provided by the straight-line method to estimated residual values over periods of approximately 25 years for flight equipment, and 5 to 30 years for ground property and equipment. As of December 31, 2023, residual values estimated for aircraft range from 13 percent to 20 percent, and generally range from 0 to 10 percent for ground property and equipment. Assets constructed for others consists of airport improvement projects in which the Company is considered to have control of the asset during the construction period. Once construction is effectively completed, the sale-leaseback model would apply when control passes from the lessee to the lessor. See Note 5 for further information. Leasehold improvements are amortized as a component of depreciation expense over the estimated useful life of the asset or the remaining term of the underlying lease, whichever is less. In certain situations, the term of the lease may include periods covered by renewal options, if renewal is reasonably certain.

limited to, significant decreases in the market value of the long-lived asset group, a significant change in the long-lived asset group’s physical condition, and operating or cash flow losses associated with the use of the long-lived asset group. If an asset group is deemed to be impaired, an impairment loss is recorded for the excess of the asset group's book value in relation to its estimated fair value. During 2022 and 2021, the Company recorded impairment charges of $28 million and $12 million, respectively, associated with the accelerated retirement of 10 and 8 of its Boeing 737-700 ("-700") aircraft. There were no material impairments in 2023 associated with the accelerated retirement of the Company's aircraft. However, the Company identified certain -700 aircraft that were retired early in 2023 or are planned for early retirement in 2024. This change in retirement dates, and the corresponding impact to depreciation expense, is considered a change in estimate and resulted in the following impact to expense in 2023:

The Company determines if an arrangement is a lease at inception. Operating leases are included in Operating lease right-of-use assets, Current operating lease liabilities, and Noncurrent operating lease liabilities in the Consolidated Balance Sheet. Finance leases are included in Property and equipment, Current maturities of long-term debt, and Long-term debt less current maturities in the Consolidated Balance Sheet.

Right-of-use assets represent the Company's right to use an underlying asset for the lease term, and lease liabilities represent the Company's obligation to make lease payments arising from the lease. The lease liability is measured as the present value of the unpaid lease payments, and the right-of-use asset value is derived from the calculation of the lease liability. Lease payments include fixed and in-substance fixed payments, variable payments based on an index or rate, reasonably certain purchase options, termination penalties, fees paid by the lessee to the owners of a special-purpose entity for restructuring the transaction, and probable amounts the lessee will owe under a residual value guarantee. Lease payments do not include (i) variable lease payments other than those that depend on an index or rate, (ii) any guarantee by the lessee of the lessor’s debt, or (iii) any amount allocated to non-lease components, if such election was made upon adoption, per the provisions of the Accounting Standards Codification ("ASC") 842. The Company uses its estimated incremental borrowing rate, which is derived from information available at the lease commencement date, in determining the present value of lease payments, since the Company does not know the actual implicit rates in its leases. The Company gives consideration to its most recent debt issuances as well as publicly available data for instruments with similar characteristics when calculating its incremental borrowing rate. Lease expense for operating lease payments is recognized on a straight-line basis over the lease term. The Company combines lease and non-lease components for all asset groups. The Company's lease term includes any option to extend the lease when it is reasonably certain to be exercised based on considering all relevant economic factors.

The Company has maintenance agreements related to certain aircraft engines with external service providers, including agreements that effectively transfer the risk of performance of such work to the service provider. Under the agreements where the risk of performance is deemed transferred to the counterparty, the appropriate expense is recorded commensurate with the period in which the corresponding level of service is provided. For its engine

The Company applies a fair value-based impairment test to the carrying value of goodwill and indefinite-lived intangible assets annually on October 1st, or more frequently if certain events or circumstances indicate that an impairment loss may have been incurred. The Company assesses the value of goodwill and indefinite-lived intangible assets under either a qualitative or quantitative approach. Under a qualitative approach, the Company considers various market factors, including applicable key assumptions also used in the quantitative assessment listed below. These factors are analyzed to determine if events and circumstances could reasonably have affected the fair value of goodwill and indefinite-lived intangible assets. If the Company determines that it is more likely than not that an indefinite-lived intangible asset or reporting unit goodwill is impaired, the quantitative approach is used to assess the asset or reporting unit fair value and the amount of the impairment. Under a quantitative approach, the fair value of the Company's indefinite-lived intangible asset or reporting unit is calculated based on key market participant assumptions. If the indefinite-lived intangible assets' carrying value exceeds the fair value calculated using the quantitative approach, an impairment charge is recorded for the difference in fair value and carrying value. If the reporting unit carrying value exceeds the reporting unit fair value calculated using the quantitative approach, an impairment charge is recorded for the difference between fair value and carrying value, limited to the amount of goodwill in the reporting unit.

The Company’s intangible assets primarily consist of acquired rights to certain airport owned takeoff and landing slots (a "slot" is the right of an air carrier, pursuant to regulations of the Federal Aviation Administration ("FAA"), to operate a takeoff or landing at a specific time at certain airports) at certain domestic slot-controlled airports. Indefinite-lived slots of $296 million are included as a component of Other assets in the Company's Consolidated Balance Sheet, as of December 31, 2023 and 2022.

Tickets sold for Passenger air travel are initially deferred as Air traffic liability. Passenger revenue is recognized and Air traffic liability is reduced when the service is provided (i.e., when the flight takes place). Air traffic liability primarily represents tickets sold for future travel dates, flight credits that are expected to be used in the future, and loyalty benefits that are expected to be redeemed in the future. The majority of the Company’s tickets sold are nonrefundable. Southwest has a No-Show policy that applies to fares that are not canceled or changed by a Customer at least ten minutes prior to a flight's scheduled departure. Nonrefundable tickets that are sold but not flown on the travel date, and are canceled in accordance with the No-Show policy, can be applied to future travel. Refundable tickets that are sold but not flown on the travel date can also be applied to future travel. A small percentage of tickets (or partial tickets) will go unused, which is sometimes referred to as breakage. The Company estimates the amount of tickets that will go unused and recognizes such amounts in Passenger revenue in proportion to the pattern of flights taken by the Customers, once the flight date has lapsed. Based on the Company's revenue recognition policy, revenue is recorded at the flight date for a Customer who does not change his/her itinerary or does not cancel in accordance with the No-Show policy as the Company has then fulfilled its performance obligation. Amounts collected from passengers for ancillary services are also recognized when the service is provided, which is typically the flight date.

of the COVID-19 pandemic. For all Customer flight credits created or that would have otherwise expired between March 1 and September 7, 2020, associated with flight cancellations, the Company previously extended the expiration date to September 7, 2022. On July 28, 2022, the Company modified its policy and announced that all unexpired flight credits as of that date, including flight credits previously extended as a result of the COVID-19 pandemic, will no longer have an expiration date and thus will be able to be redeemed by Customers indefinitely. This change in policy was considered a contract modification under ASC 606, and the Company accounted for such change prospectively in third quarter 2022. Breakage estimates are based on the Company's Customers' historical travel behavior as well as assumptions about the Customers' future travel behavior. Assumptions about the Customers' future travel behavior can be impacted by several factors including, but not limited to: fare increases; fare sales; changes to the Company's ticketing policies; changes to the Company’s refund, exchange, and unused flight credit policies; seat availability; and economic factors. As a result of the Company's policy change for flight credits in 2022, as well as changes in Customer behavior during 2020 and 2021, the amount of breakage realized on a prospective basis is expected to be lower and more stable than it has been previously. See Note 6 for further information.

Approximately $828 million, approximately $811 million, and approximately $475 million of the Company's Operating revenues in 2023, 2022, and 2021, respectively, were attributable to foreign operations. The remainder of the Company's Operating revenues, approximately $25.0 billion, approximately $23.0 billion, and approximately $15.3 billion in 2023, 2022, and 2021, respectively, were attributable to domestic operations.

The Company records a liability for the relative fair value of providing free travel under its loyalty program for all points earned from flight activity or sold to business partners participating in the Company’s Rapid Rewards loyalty program. The loyalty liability represents performance obligations that will be satisfied when a Rapid Rewards loyalty member redeems points for travel or other goods and services. Points earned from flight activity are valued at their relative standalone selling price by applying fair value based on historical redemption patterns. Points earned from business partner activity, which primarily consist of points sold, along with related marketing services, to companies participating in the Rapid Rewards loyalty program, are valued using a relative fair value methodology based on the contractual rate which partners pay to Southwest to award Rapid Rewards points to the business partner’s customers. For points that are expected to remain unused, the Company recognizes breakage in proportion to the pattern of points used by the Customer, which approximates the average period over which the population of Rapid Reward Members redeem their points. The Company records passenger revenue related to air transportation when the transportation is delivered. The marketing elements are recognized as Other - net revenue when earned. The Company’s liability for loyalty benefits includes a portion that is expected to be redeemed during the following twelve months (classified as a component of Air traffic liability), and a portion that is not expected to be redeemed during the following twelve months (classified as Air traffic liability - noncurrent). The Company continually updates this analysis and adjusts the split between current and non-current liabilities as appropriate. See Note 6 for further information.

The Company accounts for financial derivative instruments at fair value and applies hedge accounting rules where appropriate. The Company utilizes various derivative instruments, including jet fuel, crude oil, unleaded gasoline, and heating oil-based derivatives, in an attempt to reduce the risk of its exposure to jet fuel price increases. These instruments are accounted for as cash flow hedges upon proper qualification. At times, the Company can have interest rate swap agreements, the primary objective of which is to hedge forecasted debt issuances. These interest rate hedges are appropriately designated as cash flow hedges.

All cash flows associated with purchasing and selling derivatives are classified as operating cash flows in the Consolidated Statement of Cash Flows, within Changes in certain assets and liabilities. The Company classifies its cash collateral provided to or held from counterparties in a "net" presentation on the Consolidated Balance Sheet against the fair value of the derivative positions with those counterparties. See Note 11 for further information.

The Company capitalizes certain internal and external costs related to the acquisition and development of internal use software during the application development stages of projects. The Company amortizes these costs using the straight-line method over the estimated useful life of the software, which is typically five to fifteen years. Costs incurred during the preliminary project or the post-implementation/operation stages of the project are expensed as incurred. Capitalized computer software, included as a component of Ground property and equipment in the accompanying Consolidated Balance Sheet, net of accumulated depreciation, was $1 billion and $928 million as of December 31, 2023, and 2022, respectively. Computer software depreciation expense was $246 million, $232 million, and $213 million for the years ended December 31, 2023, 2022, and 2021, respectively, and is included as a component of Depreciation and amortization expense in the accompanying Consolidated Statement of Income. The Company evaluates internal use software for impairment on a quarterly basis, and if it is determined the value of an asset was not recoverable or it qualifies for impairment, a charge will be recorded to write down the software to the lower of its carrying value or fair value. The Company had no significant impairments during 2023, 2022, or 2021.

The Company uses a combination of insurance and self-insurance mechanisms, including a wholly-owned captive insurance entity and participation in a reinsurance treaty, to provide for the potential liabilities associated with certain risks, including workers’ compensation, healthcare benefits, general liability, and aviation liability. Liabilities associated with the risks that are retained by the Company are not discounted and are estimated, in part, by considering historical claims experience, demographics, exposure and severity factors and other actuarial assumptions.

The Company accounts for deferred income taxes utilizing an asset and liability method, whereby deferred tax assets and liabilities are recognized based on the tax effect of temporary differences between the financial statements and the tax basis of assets and liabilities, as measured by current enacted tax rates. The Company also evaluates the need for a valuation allowance to reduce deferred tax assets to estimated recoverable amounts.

The Company’s policy for recording interest and penalties associated with uncertain tax positions is to record such items as a component of Income (loss) before income taxes. Penalties are recorded in Other (gains) losses, net, and interest paid or received is recorded in Interest expense or Interest income, respectively, in the accompanying Consolidated Statement of Income. There were no material amounts recorded for penalties and interest related to uncertain tax positions for all years presented. See Note 15 for further information.

Approximately 83 percent of the Company’s Employees are unionized and are covered by collective-bargaining agreements. A portion of the Company's unionized Employees, including its Pilots, Flight Attendants, and Ramp Agents, which had contracts that became amendable on or before December 31, 2023, were in discussions on labor agreements as of December 31, 2023. Those unionized Employee groups in discussions represented approximately 65 percent of the Company’s Employees as of December 31, 2023. On January 22, 2024, the Company's nearly 11,000 Pilots, represented by the Southwest Airlines Pilots' Association ("SWAPA"), voted to ratify a five-year contract extension with the Company. The newly ratified agreement becomes amendable in January 2029.

To manage risk associated with financial derivative instruments held, the Company selects and will periodically review counterparties based on credit ratings, limits its exposure to a single counterparty, and monitors the market position of the program and its relative market position with each counterparty. The Company also has agreements with counterparties containing early termination rights and/or bilateral collateral provisions whereby security is required if market risk exposure exceeds a specified threshold amount or credit ratings fall below certain levels. Collateral deposits provided to or held from counterparties serve to decrease, but not totally eliminate, the credit risk associated with the Company’s hedging program. See Note 11 for further information.

As of December 31, 2023, the Company operated an all-Boeing fleet, all of which are variations of the Boeing 737. The Boeing 737 MAX aircraft ("MAX") are crucial to the Company’s growth plans and fleet modernization initiatives. Boeing has in the past experienced, and may continue to experience, delays in fulfilling its commitments with regards to delivery of the Boeing 737-8 ("-8") to the Company as a result of supply chain constraints. Further, the Company's contractual delivery schedule for the Boeing 737-7 ("-7") is dependent on the FAA issuing required certifications and approvals to Boeing and the Company. The FAA will ultimately determine the timing of the -7 certification and entry into service, and the Company therefore offers no assurances that current estimations and timelines are correct.

Boeing no longer manufactures versions of the 737 other than the MAX family of aircraft. If the MAX aircraft were to become unavailable for the Company’s flight operations, the Company’s growth would be restricted unless and until it could procure and operate other types of aircraft from Boeing or another manufacturer, seller, or lessor, and the Company’s operations would be materially adversely affected. In particular, if the Company’s growth were to be dependent upon the introduction of a new aircraft make and model to the Company’s fleet, the Company would need to, among other things, (i) develop and implement new maintenance, operating, and training programs, (ii) secure extensive regulatory approvals, and (iii) implement new technologies. The requirements associated with operating a new aircraft make and model could take an extended period of time to fulfill and would likely impose substantial costs on the Company. A shift away from a single fleet type could also add complexity to the Company’s operations, present operational and compliance risks, and materially increase the Company's costs. Any of these events would have a material, adverse effect on the Company's business, operating results, and financial condition. The Company could also be materially adversely affected if the pricing or operational attributes of its aircraft were to become less competitive.

The Company has historically entered into agreements with some of its co-brand, payment, and loyalty partners that contain exclusivity aspects which place certain confidential restrictions on the Company from entering into certain arrangements with other payment and loyalty partners. These arrangements generally extend for the terms of the agreements, none of which currently extend beyond October 31, 2030. Some of these agreements automatically renew on an annual basis, unless either party objects to such extension. None of these agreements are more than 10 years in length. The Company believes the financial benefits generated by the exclusivity aspects of these arrangements outweigh the risks involved with such agreements.