APS 2012 Annual Report Download - page 181

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Because of the inherent limitations of internal control over financial reporting, including the
possibility of collusion or improper management override of controls, material misstatements due to
error or fraud may not be prevented or detected on a timely basis. Also, projections of any evaluation
of the effectiveness of the internal control over financial reporting to future periods are subject to the
risk that the controls may become inadequate because of changes in conditions, or that the degree of
compliance with the policies or procedures may deteriorate.
In our opinion, the consolidated financial statements referred to above present fairly, in all material
respects, the financial position of Arizona Public Service Company and subsidiary as of
December 31, 2012 and 2011, and the results of their operations and their cash flows for each of the
three years in the period ended December 31, 2012, in conformity with accounting principles
generally accepted in the United States of America. Also, in our opinion, such financial statement
schedule, when considered in relation to the basic consolidated financial statements taken as a whole,
present fairly, in all material respects, the information set forth therein. Also, in our opinion, the
Company maintained, in all material respects, effective internal control over financial reporting as of
December 31, 2012, based on the criteria established in Internal Control — Integrated Framework
issued by the Committee of Sponsoring Organizations of the Treadway Commission.
As discussed in Note 2 to the consolidated financial statements, the Company has changed its method
of presenting comprehensive income in 2012 due to the adoption of amended guidance on the
presentation of comprehensive income. The change in presentation has been applied retrospectively
to all periods presented.
Deloitte & Touche LLP
Phoenix, Arizona
February 22, 2013