Ultra Clean Holdings Inc

Evaluation of Disclosure Controls and Procedures

Under the supervision and with the participation of our management, including our chief executive officer and chief financial officer, we conducted an evaluation of our disclosure controls and procedures, as such term is defined in Rule 13a-15(e) under the Exchange Act. Disclosure controls and procedures are designed to ensure that information required to be disclosed by us in the reports we file or submit under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms and that such information is accumulated and communicated to management, including the chief executive officer and chief financial officer, as appropriate, to allow timely decisions regarding required disclosure. Based upon this evaluation, our chief executive officer and our chief financial officer concluded the disclosure controls and procedures were not effective as of December 27, 2024, the end of the period covered by this Annual Report on Form 10-K, due to material weaknesses in internal control over financial reporting described below.

Management’s Report on Internal Control Over Financial Reporting

Management is responsible for establishing and maintaining adequate internal control over financial reporting. Internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external reporting purposes in accordance with generally accepted accounting principles.

Management of the Company has assessed the effectiveness of the Company’s internal control over financial reporting as of December 27, 2024 using the criteria described in Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). Because of the material weaknesses described below, management concluded that the Company did not maintain effective internal control over financial reporting as of December 27, 2024.

A material weakness is a deficiency, or a combination of deficiencies, in internal control over financial reporting, such that there is a reasonable possibility that a material misstatement of the Company’s annual or interim financial statements will not be prevented or detected on a timely basis.

The Company did not design and maintain effective controls relating to the: (i) sufficiency of processes related to identifying and analyzing risks to the achievement of objectives across the Company, (ii) sufficiency of competent personnel to analyze risks of material misstatement and develop internal control activities to support the achievement of the Company’s internal control objectives; and (iii) monitoring of control activities in accordance with established policies in a timely manner.

These material weaknesses contributed to the following additional material weaknesses:

(a) The Company did not design and maintain effective information technology (“IT”) general controls for certain information systems that are relevant to the preparation of its consolidated financial statements. Specifically, for certain of the Fluid Solutions operating subsidiaries in the Products segment which have not been migrated to the Company’s primary ERP system, the Company did not design and maintain (i) program change management controls to ensure that IT program and data changes are identified, tested, authorized and implemented appropriately, and (ii) user access controls to ensure appropriate segregation of duties and to adequately restrict user and privileged access to appropriate company personnel.

(b) The Company did not design and maintain effective controls for certain other international operating subsidiaries in the Products segment. Specifically, the Company did not design and maintain effective segregation of duties controls across various business processes, including journal entries.

The material weaknesses described above did not result in any material misstatements to annual or interim consolidated financial statements. However, these material weaknesses could result in misstatements of our consolidated financial statements that would result in a material misstatement to the annual or interim consolidated financial statements that would not be prevented or detected.

The effectiveness of the Company’s internal control over financial reporting as of December 27, 2024 has been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, as stated in their report which appears under Item 8.

Remediation Plan and Progress

Management has been executing and remains committed to implementing measures designed to ensure that control deficiencies contributing to the material weaknesses are remediated, such that these controls are designed, implemented, and operating effectively.

In response to all unremediated material weaknesses, management has taken the following actions:

•engaged an external advisor to assist with evaluating and documenting the design and operating effectiveness of internal controls and to assist with the remediation of deficiencies, as necessary,

•hired additional IT, accounting, and finance personnel to support our remediation efforts, including a Vice President of Internal Audit, as well as third-party resources with relevant expertise to augment our internal resources,

•formalized roles and responsibilities within the organization to establish ownership of workstreams to identify and analyze risks of material misstatement, develop internal control activities to support the achievement of the Company’s internal control objectives, and monitor the effective performance of those control objectives,

•performed an entity-wide risk assessment of information technology systems and business processes by operating subsidiary, and

•assessed the specific training needs for newly hired and existing personnel and developed and delivered training programs designed to support our internal controls.

In response to the material weakness “(a)” management has taken the following actions:

•in process of designing and implementing change management and user access review controls for relevant information technology systems at certain Fluid Solutions operating subsidiaries not yet migrated to our primary ERP system. Management also continues to design and implement other user access controls to ensure appropriate segregation of duties that adequately restrict user access to our financial applications and data to appropriate company personnel.

In response to the material weakness “(b)” management has taken the following actions:

•in process of designing and implementing controls over segregation of duties assessments to identify key conflicts, establishing policies and procedures to maintain effective segregation of duties, and identifying and implementing mitigating controls for any key conflicts identified for certain other international operating subsidiaries in the Products segment which have not been migrated to the Company’s primary ERP system.

As we continue to evaluate and work to improve our internal control over financial reporting, we may decide to take additional measures to address the material weaknesses or modify the remediation plans described above. We believe that these actions will remediate the material weaknesses, however the material weaknesses will not be considered remediated until we conclude all measures necessary to remediate the material weaknesses have been designed, implemented, and the applicable controls have operated for a sufficient period of time, and management has concluded, through testing, that these controls are designed and operating effectively. While management believes that the aforementioned plans will remediate the material weaknesses, there is no assurance on the exact timing of the completion of the remediation.

Remediation of Previously Reported Material Weaknesses

We previously disclosed material weaknesses in our internal control over financial reporting related to the following:

•the design of controls to determine the valuation of inventories, including the write down of inventory to its estimated market value less costs to sell and the validation and approval of inventory costing,

•the design of controls to validate the accuracy of certain data used within the operation of controls which affects substantially all financial statement account balances and disclosures, and

•the design of controls related to the review of cash flow forecasts used in the valuation of certain assets and liabilities acquired in a business combination. Specifically, the control activities related to the review of the inputs and assumptions utilized to develop the cash flow forecasts used in the valuation of acquired intangible assets and contingent earn-out liabilities were not designed at an appropriate level of precision.

During the quarter ended September 27, 2024, we completed the following activities as part of remediating these material weaknesses:

•designed and implemented controls over valuation of inventories, including review and assessment of the methodology for the valuation of inventories, including the write down of inventory to its estimated market value less costs to sell,

•designed and implemented controls over validation and approval of inventory costing,

•established ongoing education and training of control owners on how to assess the accuracy and completeness of relevant data used within the operation of controls, including the adequate levels of evidence and documentation required to support such procedures,

•designed and implemented an additional control activity in each IT dependent manual control to validate the accuracy of data used within the operation of controls,

•designed and implemented controls over the review of cash flow forecasts utilized in the valuation of contingent earn-out liabilities including review of the inputs and assumptions utilized to develop the cash flow forecasts at an appropriate level of precision, and

•designed controls that stand ready to operate in a future business combination to review the inputs and assumptions utilized to develop the cash flow forecasts in the valuation of intangible assets at an appropriate level of precision.

During the quarter ended December 27, 2024, we completed our testing of both the design and operating effectiveness of these controls and have determined that controls operated for a sufficient period of time for management to conclude that these material weaknesses have been remediated as of December 27, 2024.

Changes in Internal Control Over Financial Reporting

There were no changes in our internal control over financial reporting during the fiscal fourth quarter ended December 27, 2024 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.