ONTO INNOVATION INC. Income Taxes Disclosure

Income before provision for income taxes is comprised of the following:

At January 3, 2026 and December 28, 2024, the Company had recorded valuation allowances of $15.4 million and $12.2 million, respectively, on a certain portion of the Company’s deferred tax assets to reflect the deferred tax assets at the net

amount that is more likely than not to be realized. The Company maintains a valuation allowance against its federal foreign tax credit carryforwards of $1.0 million and state research and development credits of $14.4 million.

In assessing the realizability of deferred tax assets, the Company uses a more likely than not standard. If it is determined that it is more likely than not that deferred tax assets will not be realized, a valuation allowance must be established against the deferred tax assets. The ultimate realization of the assets is dependent on the generation of future taxable income during the periods in which the associated temporary differences become deductible. Management considers the scheduled reversal of deferred income tax liabilities, projected future taxable income and tax planning strategies when making this assessment. In making the determination that it is more likely than not that the Company’s deferred tax assets will be realized as of January 3, 2026, the Company relied primarily on the reversal of deferred tax liabilities as well as projected future taxable income.

At January 3, 2026, the Company had tax effected federal, state, and foreign net operating loss carryforwards of $0.3 million, $0.9 million and $0.2 million, respectively. The federal, state and foreign net operating loss carryforwards expire on various dates beginning in 2033.

At January 3, 2026, the Company had foreign tax credit carryforwards and state research & development credits of $1.1 million, and $19.8 million, respectively. The foreign tax credit carryforwards are set to expire at various dates beginning December 31, 2030. The state research & development credit carryforwards are set to expire at various dates beginning December 31, 2028.

As of January 3, 2026, the Company has not provided U.S. income taxes on all its foreign earnings. The Company continues to permanently reinvest the cash held offshore to support its working capital needs. The Company has accrued $0.9 million for additional taxes associated with its Taiwan branch.

On July 4, 2025, the One Big Beautiful Bill Act (“The Act”) was signed into law. The Act makes permanent key elements of the Tax Cuts and Jobs Act, including 100 percent bonus depreciation, domestic research cost expensing, increases the Advanced Manufacturing Investment Credit to 35 percent from 25 percent and makes modifications to the international tax framework. The Act includes multiple effective dates, with certain provisions effective in 2025 and others phased in through 2027. The Company continues to evaluate the impact of the Act's provisions that take effect in future years.

The unrecognized tax benefits at January 3, 2026 and December 28, 2024 were $25.4 million and $13.0 million, respectively, of which $10.3 million and $6.7 million, respectively, would be reflected as an adjustment to income tax expense if recognized. The year-over-year increase from 2024to 2025 is primarily due to unrecognized tax benefits associated with the acquisition of Semilab USA, as well as build for current year unrecognized tax benefits, offset by reserve releases from expiring tax statutes.

The Company recognizes accrued interest and penalties related to unrecognized tax benefits in income tax expense. During the years ended January 3, 2026, December 28, 2024 and December 30, 2023, the Company recognized approximately $(12) thousand, $(223) thousand and $146 thousand, respectively, in interest and penalties (benefit) expense associated with uncertain tax positions. As of January 3, 2026 and December 28, 2024, the Company had accrued interest and penalties expense included in the table of unrecognized tax benefits of $545 thousand and $564 thousand, respectively.

The Company is subject to U.S. federal income tax as well as income tax in multiple state and foreign jurisdictions. The Company is subject to ordinary statute of limitation rules of three and four years for federal and state returns, respectively. However, due to tax attribute carryforwards, the Company is subject to examination for tax years 2022 forward for U.S. federal

tax purposes with respect to carryforward amounts. The Company is also subject to examination in various states for tax years 2006 forward with respect to carryforward amounts. The Company is subject to examination for tax years 2016 forward for various foreign jurisdictions. The Company believes that adequate amounts have been reserved for any adjustments that may ultimately result from any future examinations of these years.

In the normal course of business, the Company is subject to tax audits in various jurisdictions, and such jurisdictions may assess additional income taxes or other taxes against it. Although the Company believes its tax estimates are reasonable, the final determination of tax audits and any related litigation could be materially different from the Company’s historical income tax provisions and accruals. The results of an audit or litigation could have a material adverse effect on the Company’s results of operations or cash flows in the period or periods for which that determination is made.