UNS Ex 15.A 6.30.2013

We are aware that our report dated July 30, 2013, on our review of condensed consolidated interim financial information of UNS Energy Corporation (the "Company") for the three-month and six-month periods ended June 30, 2013 and 2012 and included in the Company's quarterly report on Form 10-Q for the quarter ended June 30, 2013, is incorporated by reference in its Registration Statements on Form S-8 dated January 6, 1998 (No. 333-43765), January 6, 1998 (No. 333-43767), January 6, 1998 (No. 333-43769), May 21, 1998 (No. 333-53309), May 21, 1998 (No. 333-53333), September 9, 2002 (No. 333-99317), January 31, 2007 (No. 333-140353), December 30, 2008 (No. 333-156491), and June 17, 2011 (No. 333-175001) and on Form S-3 dated May 10, 2012 (No. 333-181305).