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Basis of Presentation and Summary of Significant Accounting Policies (Policies) | 12 Months Ended
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Dec. 31, 2025
Accounting Policies [Abstract] |
Principles of Consolidation | Principles of Consolidation: The consolidated financial statements include the accounts of West Pharmaceutical Services, Inc. ("West") after the elimination of intercompany transactions. We have no participation or other rights in variable interest entities.
Use of Estimates | Use of Estimates: The financial statements are prepared in conformity with U.S. GAAP. These principles require management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingencies in the financial statements. Actual amounts realized may differ from these estimates.
Cash and Cash Equivalents | Cash and Cash Equivalents: Cash equivalents include money market funds, time deposits and all highly liquid short-term instruments with maturities of three months or less at the time of purchase.
Accounts Receivable | Accounts Receivable: Our accounts receivable balance was net of an allowance for credit losses of $1.4 million and $0.8 million for December 31, 2025 and 2024, respectively. Under the current expected credit loss model, we utilize a provision matrix approach, utilizing historical loss rates based on the number of days past due, adjusted to reflect current economic conditions and forecasts of future economic conditions.
Inventories | Inventories: Inventories are valued at the lower of cost (on a first-in, first-out basis) or net realizable value.
Property, Plant and Equipment | Property, Plant and Equipment: Property, plant and equipment assets are carried at cost. Maintenance and minor repairs and renewals are charged to expense as incurred. Costs incurred for computer software developed or obtained for internal use are capitalized for application development activities and immediately expensed for preliminary project activities or post-implementation activities. Upon sale or retirement of depreciable assets, costs and related accumulated depreciation are eliminated, and gains or losses are recognized in other expense (income). Depreciation and amortization are computed principally using the straight-line method over the estimated useful lives of the assets, or the remaining term of the lease, if shorter.
Leases | Leases: Lease right-of-use assets are initially measured at cost, which comprises the initial amount of the lease liability adjusted for lease payments made at or before the lease commencement date, plus any initial direct costs incurred less any lease incentives received. Lease right-of-use assets are subsequently measured throughout the lease term at the carrying amount of the lease liability, plus initial direct costs, plus (minus) any prepaid (accrued) lease payments, less the unamortized balance of lease incentives received. Lease expense for operating leases is recognized on a straight-line basis over the lease term. Conversely, lease expense for finance leases is a front loaded expense recognition pattern over the lease term. Lease liabilities are initially measured at the present value of the unpaid lease payments at the lease commencement date.
Impairment of Long-Lived Assets | Impairment of Long-Lived Assets: Long-lived assets, including property, plant and equipment, operating lease right-of-use assets and finance lease right-of-use assets, are tested for impairment whenever circumstances indicate that the carrying value of these assets may not be recoverable. An asset is considered impaired if the carrying value of the asset exceeds the sum of the future expected undiscounted cash flows to be derived from the asset. Once an asset is considered impaired, an impairment loss is recorded within other expense (income) for the difference between the asset’s carrying value and its fair value. For assets held and used in the business, management determines fair value using estimated future cash flows to be derived from the asset, discounted to a net present value using an appropriate discount rate. For assets held for sale or for investment purposes, management determines fair value by estimating the proceeds to be received upon sale of the asset, less disposition costs.
Impairment of Goodwill and Other Intangible Assets | Impairment of Goodwill and Other Intangible Assets: Goodwill is tested for impairment at least annually, following the completion of our annual budget and long-range planning process, or whenever circumstances indicate that the carrying value of these assets may not be recoverable. Goodwill is tested for impairment at the reporting unit level, which is the same as, or one level below, our operating segments. A goodwill impairment charge represents the amount by which a reporting unit’s carrying amount exceeds its fair value, not to exceed the total amount of goodwill allocated to that reporting unit. Accounting guidance also allows entities to first assess qualitative factors, including macroeconomic conditions, industry and market considerations, cost factors, and overall financial performance, to determine whether it is necessary to perform the quantitative goodwill impairment test. If, based upon our assessment, we determined that it was not more likely than not that the fair value of each of our reporting units was less than its carrying amount, then it would not be necessary to perform the quantitative goodwill impairment test. We elected to follow this guidance for our annual impairment test. Based upon our assessment, we determined that it was not more likely than not that the fair value of each of our reporting units was less than its carrying amount and determined that it was not necessary to perform the quantitative goodwill impairment test in the current year. Valuing identifiable intangible assets requires judgment. For example, for recent identifiable customer relationship intangible asset acquisitions, we applied an excess earnings model, which is a form of the income approach. This approach includes projecting revenues and expenses attributable to the existing customers over the remaining economic life of the customer relationships and then subtracting the required return on net tangible assets and any intangible assets used in the business to estimate any residual excess earnings attributable to the customer relationships. The after-tax excess earnings are then discounted to present value using the respective discount rates. Intangible assets with finite lives are amortized using the straight-line method over their estimated useful lives of 3 to 25 years and reviewed for impairment whenever circumstances indicate that the carrying value of these assets may not be recoverable. Factors that could trigger an impairment review include the following: 1) significant under-performance relative to historical or projected future operating results; 2) significant changes in the manner or use of the acquired assets or the strategy of the overall business; 3) significant negative industry or economic trends; and 4) recognition of goodwill impairment charges. If we determine that the carrying value of identifiable intangibles assets may not be recoverable based on the existence of one or more of the above indicators of impairment, we measure recoverability of assets by comparing the respective carrying value of the assets to the current and expected future cash flows, on an undiscounted basis, to be generated from such assets. If such analysis indicates that the carrying value of these assets is not recoverable, we measure an impairment based on the amount in which the net carrying amount of the assets exceeds the fair values of the assets.
Employee Benefits | Employee Benefits: The measurement of the obligations under our defined benefit pension and postretirement medical plans are subject to a number of assumptions. These include the rate of return on plan assets (for funded plans) and the rate at which the future obligations are discounted to present value. For our funded plans, we consider the current and expected asset allocations of our plan assets, as well as historical and expected rates of return, in estimating the long-term rate of return on plan assets. U.S. GAAP requires the recognition of an asset or liability for the funded status of a defined benefit postretirement plan, as measured by the difference between the fair value of plan assets, if any, and the benefit obligation. For a pension plan, the benefit obligation is the projected benefit obligation; for any other postretirement plan, such as a retiree health plan, the benefit obligation is the accumulated postretirement benefit obligation. Please refer to Note 15, Benefit Plans, for a more detailed discussion of our pension and other retirement plans.
Financial Instruments | Financial Instruments: All derivatives are recognized as either assets or liabilities in the balance sheet and recorded at their fair value. For a derivative designated as a hedge of the exposure to variable cash flows of a forecasted transaction (referred to as a cash flow hedge), the effective portion of the derivative’s gain or loss is initially reported as a component of other comprehensive income (“OCI”), net of tax, and subsequently reclassified into earnings when the forecasted transaction affects earnings. For a derivative designated as a hedge of the exposure to changes in the fair value of a recognized asset or liability or a firm commitment (referred to as a fair value hedge), the derivative’s gain or loss is recognized in earnings in the period of change together with the offsetting loss or gain on the hedged item. For a derivative designated as a hedge of the foreign currency exposure of a net investment in a foreign operation, the gain or loss is reported in OCI, net of tax, as part of the cumulative translation adjustment. The ineffective portion of any derivative used in a hedging transaction is recognized immediately into earnings. Derivative financial instruments that are not designated as hedges are also recorded at fair value, with the change in fair value recognized immediately into earnings. We do not purchase or hold any derivative financial instrument for investment or trading purposes.
Foreign Currency Translation | Foreign Currency Translation: Foreign currency transaction gains and losses are recognized in the determination of net income. Foreign currency translation adjustments of subsidiaries and affiliates operating outside of the U.S. are accumulated in other comprehensive loss, a separate component of equity.
Revenue Recognition | Revenue Recognition: Our revenue results from the sale of goods or services and reflects the consideration to which we expect to be entitled in exchange for those goods or services. We record revenue based on a five-step model, in accordance with Accounting Standards Codification (“ASC”) 606. Following the identification of a contract with a customer, we identify the performance obligations (goods or services) in the contract, determine the transaction price, allocate the transaction price to the performance obligations in the contract, and recognize the revenue when (or as) we satisfy the performance obligations by transferring the promised goods or services to our customers. A good or service is transferred when (or as) the customer obtains control of that good or service. We have elected to disregard the effects of a significant financing component, as we expect, at the inception of our contracts, that the period between when we transfer a promised good or service to the customer and when the customer pays for that good or service will be one year or less. We recognize the majority of our revenue, primarily relating to Proprietary Products product sales, at a point in time, following the transfer of control of our products to our customers, which typically occurs upon shipment or delivery, depending on the terms of the related agreements. We recognize revenue relating to our Contract-Manufactured Products product sales and certain Proprietary Products product sales over time, as our performance does not create an asset with an alternative use to us and we have an enforceable right to payment for performance completed to date. We recognize revenue relating to our development and tooling agreements over time, as our performance creates or enhances an asset that the customer controls as the asset is created or enhanced. For revenue recognized over time, revenue is recognized by applying a method of measuring progress toward complete satisfaction of the related performance obligation. When selecting the method for measuring progress, we select the method that best depicts the transfer of control of goods or services promised to our customers. Revenue for our Contract-Manufactured Products product sales, certain Proprietary Products product sales, and our development and tooling agreements is recorded under an input method, which recognizes revenue on the basis of our efforts or inputs to the satisfaction of a performance obligation (for example, resources consumed, labor hours expended, costs incurred, time elapsed, or machine hours used) relative to the total expected inputs to the satisfaction of that performance obligation. The input method that we use is based on costs incurred.
Shipping and Handling Costs | Shipping and Handling Costs: Shipping and handling costs are included in cost of goods and services sold. Shipping and handling costs billed to customers in connection with the sale are included in net sales.
Research and Development | Research and Development: Research and development expenditures are for the creation, engineering and application of new or improved products and processes. Expenditures include salaries and outside services for those directly involved in research and development activities and are primarily expensed as incurred.
Litigation | Litigation: From time to time, we are involved in legal proceedings, investigations and claims generally incidental to our normal business activities. In accordance with U.S. GAAP, we accrue for loss contingencies when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. These estimates are based on an analysis made by internal and external legal counsel considering information known at the time. Legal costs in connection with loss contingencies are expensed as incurred.
Income Taxes | Income Taxes: Deferred income taxes are recognized by applying enacted statutory tax rates to tax loss carryforwards and temporary differences between the tax basis and financial statement carrying values of our assets and liabilities. The enacted statutory tax rate applied is based on the rate expected to be applicable at the time of the forecasted utilization of the loss carryforward or reversal of the temporary difference. Valuation allowances on deferred tax assets are established when it is more likely than not that all or a portion of a deferred tax asset will not be realized. The realizability of deferred tax assets is subject to our estimates of future taxable income, generally at the respective subsidiary company and the country level. Please refer to Note 17, Income Taxes, for additional information. We recognize interest costs related to income taxes in interest expense and penalties within other expense (income). The tax law ordering approach is used for purposes of determining whether an excess tax benefit has been realized during the year.
Stock-Based Compensation | Stock-Based Compensation: Under the fair value provisions of U.S. GAAP, stock-based compensation cost is measured at the grant date based on the value of the award and is recognized as expense over the vesting period. In order to determine the fair value of stock options on the grant date, we use the Black-Scholes valuation model.
Net Income Per Share | Net Income Per Share: Basic net income per share is computed by dividing net income attributable to common shareholders by the weighted average number of shares of common stock outstanding during each period. Net income per share assuming dilution considers the dilutive effect of outstanding stock options and other stock awards based on the treasury stock method. The treasury stock method assumes the use of exercise proceeds to repurchase common stock at the average fair market value in the period.
Recently Adopted Standards and Standards Issued Not Yet Adopted | Recently Adopted Standards In December 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2023-09, Income Taxes: Improvements to Income Tax Disclosures, that seeks to enhance income tax disclosures to provide information to better assess how an entity's operations and related tax risks affect its tax rate and prospects for future cash flows. Within the income tax rate reconciliation, the amendment requires disclosure of additional categories and greater detail about individual reconciling items over a specified threshold. It also requires information pertaining to taxes paid to be disaggregated for federal, state, and foreign taxes and further disaggregated for specific jurisdictions over a specified threshold. This guidance is effective for fiscal years beginning after December 15, 2024. The Company has adopted and implemented the applicable disclosure requirements within this annual report on a prospective basis. Standards Issued Not Yet Adopted In November 2024, the FASB issued ASU No. 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, that seeks to improve the disclosures about a public business entity’s expenses and address requests from investors for more detailed information about the types of expenses (including purchases of inventory, employee compensation, depreciation, amortization, and depletion) in commonly presented expense captions. The amendments require that at each interim and annual reporting period an entity: (1) disclose the amounts of purchases of inventory, employee compensation, depreciation, and intangible asset amortization included in each of the Company's relevant expense captions; (2) include certain amounts that are already required to be disclosed under current GAAP in the same disclosure as the other disaggregation requirements; (3) disclose a qualitative description of the amounts remaining in relevant expense captions that are not separately disaggregated quantitatively; and (4) disclose the total amount of selling expenses and, in annual reporting periods, an entity’s definition of selling expenses. This guidance is effective for fiscal years beginning after December 15, 2026. The Company is currently evaluating the impact of this guidance on our financial statements and disclosures.
Fair Value Measurement | Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The following fair value hierarchy classifies the inputs to valuation techniques used to measure fair value into one of three levels: •Level 1: Unadjusted quoted prices in active markets for identical assets or liabilities. •Level 2: Inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. •Level 3: Unobservable inputs that reflect the reporting entity’s own assumptions.

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