COMPASS Pathways plc

To the Board of Directors and Shareholders of COMPASS Pathways plc

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of COMPASS Pathways plc and its subsidiaries (the “Company”) as of December 31, 2023 and 2022, and the related consolidated statements of operations and comprehensive loss, of shareholders’ equity, and of cash flows for each of the three years in the period ended December 31, 2023, including the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2023 and 2022, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2023 in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (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 of these consolidated financial statements 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 consolidated financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated 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 consolidated 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 consolidated 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 consolidated financial statements that was communicated or required to be communicated to the audit committee and that (i) relates to accounts or disclosures that are material to the consolidated financial statements and (ii) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated 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.

As described in Notes 2 and 3 to the consolidated financial statements, the Company carries out extensive research and development (“R&D”) activities and benefits from the UK R&D tax credit regime under the scheme for small and medium-sized enterprises (“SME”). For the year ended December 31, 2023, the Company recognized $12.9 million in benefit from R&D tax credit. As disclosed by management, they evaluate which UK R&D tax credit programs the Company is expected to be eligible for, that they plan to submit a claim for and have reasonable assurance that the amount will ultimately be realized. Management assesses the Company’s R&D activities and expenditures to determine whether the nature of the activities and expenditures will qualify for credit under the SME regime and whether the claim will ultimately be realized based on the allowable reimbursable expense criteria established by the UK government. Management makes judgements and estimates relating to the allocation of time spent on R&D activities by individuals.

The principal considerations for our determination that performing procedures relating to benefit from research and development tax credit is a critical audit matter are (i) the significant judgement by management when determining the nature and amount of expenses that qualify under the tax credit program, including estimating the allocation of time spent by individuals on R&D activities; and (ii) a high degree of auditor judgement, subjectivity and effort in performing procedures and evaluating audit evidence related to the benefit from R&D tax credit.

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, among others, (i) evaluating management’s assessment of the nature of the activities performed by the Company and their qualification for the R&D tax credit program available for small and medium sized enterprises, (ii) testing management’s process for determining R&D costs that qualify for the SME regime, (iii) evaluating the appropriateness of management’s allocation of qualifying expenses including determining the amount expected to be realized based on relevant criteria outlined in the tax credit program, (iv) testing the completeness and accuracy of the data used in the R&D tax credit calculations, and (v) obtaining evidence over the recoverability of the prior year claim given that the cash has not yet been received, to support the assessment that the benefit will ultimately be realized.

/s/PricewaterhouseCoopers LLP

Reading, United Kingdom

February 29, 2024

We have served as the Company's auditor since 2018.