Custom Truck One Source, Inc.

(a)Evaluation of Disclosure Controls and Procedures

In accordance with Securities Exchange Act Rules 13a-15(e) and 15d-15(e), our management, under the supervision of our Chief Executive Officer and Chief Financial Officer, conducted an evaluation of the effectiveness of the design and operation of our disclosure controls and procedures as of September 30, 2026. Based upon that evaluation, our Chief Executive Officer and Chief Financial Officer concluded that our disclosure controls and procedures were effective as of September 30, 2026.

(b)Changes to Internal Control Over Financial Reporting

There have been no changes in our internal control over financial reporting that occurred during the fiscal quarter ended September 30, 2026 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

PART II - OTHER INFORMATION

We may, at any given time, be named as a defendant in certain lawsuits, investigations and claims arising in the ordinary course of business. While the outcome of these potential lawsuits, investigations and claims cannot be predicted with certainty, we do not expect these matters to have a material adverse impact on our business, results of operations, cash flows or financial condition. In the opinion of management, there are no pending litigation, disputes or claims against the Company that, if decided adversely, would have a material adverse effect on its consolidated financial condition, cash flows or results of operations.