Vertex Inc

Shareholders and the Board of Directors of Vertex, Inc.

King of Prussia, Pennsylvania

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Vertex, Inc. (the "Company") as of December 31, 2024 and 2023, the related consolidated statements of comprehensive loss, stockholders’ equity, and cash flows for each of the three years in the period ended December 31, 2024, and the related notes (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2024 and 2023, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2024, in conformity with accounting principles generally accepted in the United States of America.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (“PCAOB”), the Company’s internal control over financial reporting as of December 31, 2024, based on criteria established in Internal Control – Integrated Framework: (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO) and our report dated February 27, 2025 expressed an unqualified opinion.

Basis for Opinion

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company's financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of the critical audit matter does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Valuation of Developed Technology and Earn-Outs in the ecosio GmbH Acquisition

As described in Notes 3 and 5, the Company completed the acquisition of ecosio GmbH for consideration of $169.83 million and the transaction was accounted for as a business combination. The acquired intangible assets included developed technology valued at $63.80 million. The total purchase consideration for the acquisition included a cash earn-out, with an aggregate of up to $94.36 million, and a stock earn-out, with an aggregate value of up to $35.00 million, collectively valued at $105.00 million as of the acquisition date. The Company used a discounted cash flow methodology to value the acquired developed technology at fair value on the date of acquisition. The Company used a Monte Carlo simulation model to value the cash and stock earn-outs. The methods used to estimate the fair value of acquired developed technology and earn-outs involve significant assumptions. The significant assumptions applied by management in estimating the fair value of acquired developed technology included cash flow projections and discount rates.

The principal considerations for our determination that auditing the valuation of developed technology and earn-outs in the ecosio acquisition is a critical audit matter are (1) there was a high degree of auditor judgment and subjectivity in applying procedures relating to the fair value of the developed technology acquired and earn-outs due to the significant judgment by management when developing the cash flow estimates and (2) significant audit effort was required in evaluating the significant assumptions relating to the basis and subjectivity of significant estimates, including the cash flow projections, revenue growth rates, cost of sales and margin projections, obsolescence curve, and discount rates. In addition, the audit effort involved the use of professionals with specialized skill and knowledge to assist in performing these procedures and evaluating the audit evidence obtained.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included:

/s/Crowe LLP

We have served as the Company's auditor since 2019.

Oakbrook Terrace, Illinois

February 27, 2025