These financial statements have been prepared and delivered in accordance with the provisions applicable to companies subject to the small companies regime.

The directors of the company have elected not to include a copy of the profit and loss account within the financial statements.true

Power Integrations UK Limited (the "company") is a private company limited by shares and incorporated in England and Wales. The registered office is 1st Floor Radio House, St Andrews Road, Cambridge, CB4 1DL.

These financial statements have been prepared in accordance with FRS 102 “The Financial Reporting Standard applicable in the UK and Republic of Ireland” (“FRS 102”) and the requirements of the Companies Act 2006 as applicable to companies subject to the small companies regime. The disclosure requirements of section 1A of FRS 102 have been applied other than where additional disclosure is required to show a true and fair view.

The financial statements are prepared in sterling, which is the functional currency of the company. Monetary amounts in these financial statements are rounded to the nearest £1.

The financial statements have been prepared under the historical cost convention. The principal accounting policies adopted are set out below.

For the year ended 31 December 2025, the company made a profit of £228,303 (2024: £423,389). At the time of approving the financial statements, the directors have a reasonable expectation that the company has adequate resources to continue in operational existence for the foreseeable future due to the continued support of the ultimate parent company through the cost-plus agreements in place for a period of at least 12 months from the date of signing of these financial statements.

Thus, the directors continue to adopt the going concern basis of accounting in preparing the financial

statements.,

The turnover shown in the statement of comprehensive income represents amounts receivable from a fellow group company during the period, for the provision of research and development services.

Turnover in respect of services provided to the fellow group company is calculated as attributable costs plus a mark up in accordance with a transfer pricing agreement between Power Integrations UK Limited and Power Integrations Limited, a fellow group company.

R&D expenditure credit ("RDEC") income is recognised when right to receive payment has been established.

Research expenditure is written off against profits in the year in which it is incurred.

Intangible assets acquired separately from a business are recognised at cost and are subsequently measured at cost less accumulated amortisation and accumulated impairment losses.

Amortisation is recognised so as to write off the cost of assets less their residual values over their useful lives on the following bases:

Tangible fixed assets are initially measured at cost and subsequently measured at cost, net of depreciation and any impairment losses.

Depreciation is recognised so as to write off the cost of assets less their residual values over their useful lives on the following bases:

The gain or loss arising on the disposal of an asset is determined as the difference between the sale proceeds and the carrying value of the asset, and is credited or charged to profit or loss.

Cash and cash equivalents are basic financial assets and include cash in hand and deposits held at call with banks.

The company has elected to apply the provisions of Section 11 ‘Basic Financial Instruments’ and Section 12 ‘Other Financial Instruments Issues’ of FRS 102 to all of its financial instruments.

Financial instruments are recognised in the company's balance sheet when the company becomes party to the contractual provisions of the instrument.

Financial assets and liabilities are offset, with the net amounts presented in the financial statements, when there is a legally enforceable right to set off the recognised amounts and there is an intention to settle on a net basis or to realise the asset and settle the liability simultaneously.

Basic financial assets, which include other debtors, amounts owed by group undertakings, and cash and bank balances, are initially measured at transaction price including transaction costs and are subsequently carried at amortised cost using the effective interest method unless the arrangement constitutes a financing transaction, where the transaction is measured at the present value of the future receipts discounted at a market rate of interest. Financial assets classified as receivable within one year are not amortised.

Financial assets, other than those held at fair value through profit and loss, are assessed for indicators of impairment at each reporting end date.

Financial assets are impaired where there is objective evidence that, as a result of one or more events that occurred after the initial recognition of the financial asset, the estimated future cash flows have been affected. If an asset is impaired, the impairment loss is the difference between the carrying amount and the present value of the estimated cash flows discounted at the asset’s original effective interest rate. The impairment loss is recognised in profit or loss.

If there is a decrease in the impairment loss arising from an event occurring after the impairment was recognised, the impairment is reversed. The reversal is such that the current carrying amount does not exceed what the carrying amount would have been, had the impairment not previously been recognised. The impairment reversal is recognised in profit or loss.

Financial assets are derecognised only when the contractual rights to the cash flows from the asset expire or are settled, or when the company transfers the financial asset and substantially all the risks and rewards of ownership to another entity, or if some significant risks and rewards of ownership are retained but control of the asset has transferred to another party that is able to sell the asset in its entirety to an unrelated third party.

Financial liabilities and equity instruments are classified according to the substance of the contractual arrangements entered into. An equity instrument is any contract that evidences a residual interest in the assets of the company after deducting all of its liabilities.

Basic financial liabilities, including trade and other creditors, are initially recognised at transaction price unless the arrangement constitutes a financing transaction, where the debt instrument is measured at the present value of the future payments discounted at a market rate of interest. Financial liabilities classified as payable within one year are not amortised.

Debt instruments are subsequently carried at amortised cost, using the effective interest rate method.

Trade creditors are obligations to pay for goods or services that have been acquired in the ordinary course of business from suppliers. Amounts payable are classified as current liabilities if payment is due within one year or less. If not, they are presented as non-current liabilities. Trade creditors are recognised initially at transaction price and subsequently measured at amortised cost using the effective interest method.

Financial liabilities are derecognised when the company’s contractual obligations expire or are discharged or cancelled.

Equity instruments issued by the company are recorded at the proceeds received, net of transaction costs. Dividends payable on equity instruments are recognised as liabilities once they are no longer at the discretion of the company.

The tax expense represents the sum of the tax currently payable and deferred tax.

The tax currently payable is based on taxable profit for the year. Taxable profit differs from net profit as reported in the profit and loss account because it excludes items of income or expense that are taxable or deductible in other years and it further excludes items that are never taxable or deductible. The company’s liability for current tax is calculated using tax rates that have been enacted or substantively enacted by the reporting end date.

Deferred tax liabilities are generally recognised for all timing differences and deferred tax assets are recognised to the extent that it is probable that they will be recovered against the reversal of deferred tax liabilities or other future taxable profits. Such assets and liabilities are not recognised if the timing difference arises from goodwill or from the initial recognition of other assets and liabilities in a transaction that affects neither the tax profit nor the accounting profit.

The carrying amount of deferred tax assets is reviewed at each reporting end date and reduced to the extent that it is no longer probable that sufficient taxable profits will be available to allow all or part of the asset to be recovered. Deferred tax is calculated at the tax rates that are expected to apply in the period when the liability is settled or the asset is realised. Deferred tax is charged or credited in the profit and loss account, except when it relates to items charged or credited directly to equity, in which case the deferred tax is also dealt with in equity. Deferred tax assets and liabilities are offset when the company has a legally enforceable right to offset current tax assets and liabilities and the deferred tax assets and liabilities relate to taxes levied by the same tax authority.

The costs of short-term employee benefits are recognised as a liability and an expense, unless those costs are required to be recognised as part of the cost of stock or fixed assets.

The cost of any unused holiday entitlement is recognised in the period in which the employee’s services are received.

Termination benefits are recognised immediately as an expense when the company is demonstrably committed to terminate the employment of an employee or to provide termination benefits.

Retirement benefits

For defined contribution schemes the amount charged to profit or loss is the contributions payable in the year.

Differences between contributions payable in the year and contributions actually paid are shown as accruals

The ultimate parent company, Power Integrations Inc., has engaged in equity-settled share-based

transactions with certain employees of the company. The transactions are settled in the ultimate parent company's equity, and are recharged to the company based on a reasonable allocation of the expense for the year.

Equity-settled share-based payments are measured at fair value at the date of grant by reference to the fair value of the equity instruments granted. The fair value determined at the grant date is expensed on a straight-line basis over the vesting period, based on the estimate of shares that will eventually vest.

The fair value of restricted stock units is determined using the fair value of the ultimate parent company's common stock on the date of the grant, reduced by the discounted present value of dividends expected to be declared before the awards vest.

Transactions in currencies other than pounds sterling are recorded at the rates of exchange prevailing at the dates of the transactions. At each reporting end date, monetary assets and liabilities that are denominated in foreign currencies are retranslated at the rates prevailing on the reporting end date. Gains and losses arising on translation in the period are included in profit or loss.

Leases

Rentals payable under operating leases, including any lease incentives received, are charged to profit or loss on a straight line basis over the term of the relevant lease except where another more systematic basis is more representative of the time pattern in which economic benefits from the leases asset are consumed.

In the application of the company’s accounting policies, the directors are required to make judgements, estimates and assumptions about the carrying amount of assets and liabilities that are not readily apparent from other sources. The estimates and associated assumptions are based on historical experience and other factors that are considered to be relevant. Actual results may differ from these estimates.

The estimates and underlying assumptions are reviewed on an ongoing basis. Revisions to accounting estimates are recognised in the period in which the estimate is revised where the revision affects only that period, or in the period of the revision and future periods where the revision affects both current and future periods.

The directors consider there to be no key judgements that are material to the company.

The estimates and assumptions which have a significant risk of causing a material adjustment to the carrying amount of assets and liabilities are as follows:

The directors consider that the key source of estimation uncertainty relates to the assessment of research and development expenditure in order to determine whether or not it is appropriate to capitalise it onto the statement of financial position in accordance with Section 18 'Intangible Assets other than Goodwill' of FRS 102.

The directors believe that it is not possible to separately identify the expenditure attributable to development activities which meet the criteria of Section 18 of FRS 102. Given this, all research and development expenditure has been recorded as an expense through the statement of comprehensive income.

The ultimate parent company, Power Integrations Inc., has engaged in equity-settled share-based

transactions with certain employees of the company. The transactions are settled in the ultimate parent company's equity, and are recharged to the company based on a reasonable allocation of the expense for the year.

Equity-settled share-based payments are measured at fair value at the date of grant by reference to the fair value of the equity instruments granted. The fair value determined at the grant date is expensed on a straight-line basis over the vesting period, based on the estimate of shares that will eventually vest.

The fair value of restricted stock units is determined using the fair value of the ultimate parent company's common stock on the date of the grant, reduced by the discounted present value of dividends expected to be declared before the awards vest.

The average monthly number of persons (including directors) employed by the company during the year was:

Following the acquisition by Power Integrations Inc. group, the ultimate parent company made its stock plan available to employees of Power Integrations UK Limited. Grants in the ultimate parent company's equity are typically made in the form of restricted stock units (RSUs) which vest over 4 years. RSUs are forfeited if the employee leaves the company prior to vesting.

The awards outstanding at 31 December 2025 have a remaining contractual life of 1.25 years.

During the year, the company recognised total share-based payment expenses of £362,844 (2024: £535,250) which related to equity settled share based payment transactions.

Voting

All shares rank equally on a one share one vote basis except Deferred shares, AA Ordinary shares and BB Ordinary shares which have no voting rights.

Conversion rights

Any individual holder of Preferred shares may at any time convert the whole of their Preferred shares into Ordinary shares and the holders of all of the Preferred shares may at any time convert all of the Preferred shares into Ordinary shares. The rate of conversion shall be one Ordinary share for each Preferred share held. All of the Preferred shares shall immediately before a qualifying IPO convert automatically into Ordinary shares at the conversion rate.

Subject to Investor majority consent, all of the Preferred shares shall immediately before a qualifying IPO convert automatically into Ordinary shares at the conversion rate.

As the income statement has been omitted from the filing copy of the financial statements, the following information in relation to the audit report on the statutory financial statements is provided in accordance with s444(5B) of the Companies Act 2006.

The auditor's report is unqualified and includes the following:

In our opinion the financial statements:

• give a true and fair view of the state of the company's affairs as at 31 December 2025 and of its profit for the year then ended;

• have been properly prepared in accordance with United Kingdom Generally Accepted Accounting Practice; and

• have been prepared in accordance with the requirements of the Companies Act 2006.

At the reporting date, the company had outstanding commitments for future minimum lease payments under non-cancellable operating leases, as follows:

The ultimate parent company is Power Integrations Inc., a company incorporated in the state of Delaware, United States of America. The smallest and largest group in which the results of Power Integrations UK Limited are consolidated is that headed by Power Integrations Inc., whose principal place of business is, 5245 Hellyer Avenue, San Jose, California, 95138. Consolidated financial statements may be obtained from the above address.