UNITIL CORP

Disclosure Controls and Procedures

Management of the Company, under the supervision and with the participation of the Company’s Chief Executive Officer, Chief Financial Officer, and Chief Accounting Officer, conducted an evaluation of the effectiveness of the design and operation of the Company’s disclosure controls and procedures as of December 31, 2025. Based on this evaluation, the Company’s Chief Executive Officer, Chief Financial Officer, and Chief Accounting Officer concluded as of December 31, 2025 that the Company’s disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) were effective.

Management’s Report on Internal Control over Financial Reporting

Management is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Exchange Act Rules 13a-15(f) and 15d-15(f).

Under the supervision and with the participation of management, including the Chief Executive Officer, Chief Financial Officer, and Chief Accounting Officer, the Company’s management has evaluated the effectiveness of the Company’s internal control over financial reporting as of December 31, 2025, based upon criteria established in the “Internal Control–Integrated Framework” (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission. Based on this evaluation, the Company’s management concluded that the Company’s internal control over financial reporting was effective as of December 31, 2025. There were no material changes in internal control over financial reporting during the year ended December 31, 2025 that materially affected, or are reasonably likely to materially affect, the Company’s internal control over financial reporting. Management continues to evaluate and enhance controls related to significant estimates, including regulatory assets, revenue recognition, and pension and postretirement obligations.

Management's assessment of the effectiveness of the Company's internal control over financial reporting as of December 31, 2025 excluded the internal controls of Maine Natural Gas Corporation, which was acquired on October 31, 2025. Maine Natural Gas Corporation's total assets and total revenues represented approximately 4.9% and 1.5%, respectively, of the Company's consolidated total assets and revenues as of and for the year ended December 31, 2025.

Deloitte & Touche LLP, an independent registered public accounting firm, has audited the effectiveness of the Company’s internal control over financial reporting as of December 31, 2025, as stated in their report which appears in Part II, Item 8 herein.

Changes in Internal Control over Financial Reporting

Except as described above, there have been no changes in the Company’s internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) during the fiscal quarter ended December 31, 2025 that have materially affected, or are reasonably likely to materially affect, the Company’s internal control over financial reporting.