Exhibit 12.3

PINNACLE WEST CAPITAL CORPORATION

RATIO OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED

STOCK DIVIDEND REQUIREMENTS

(dollars in thousands)

	Nine Months Ended September 30,		Twelve Months Ended December 31,
	2017		2016		2015		2014		2013		2012
Earnings:
Income from continuing operations attributable to common shareholders	$	466,827	$	442,034	$	437,257	$	397,595	$	406,074	$	387,380
Income taxes	237,497		236,411		237,720		220,705		230,591		237,317
Fixed charges	168,714		213,973		202,465		208,226		206,089		219,437
Total earnings	$	873,038	$	892,418	$	877,442	$	826,526	$	842,754	$	844,134
Fixed Charges:
Interest expense	$	162,477	$	205,720	$	194,964	$	200,950	$	201,888	$	214,616
Estimated interest portion of annual rents	6,237		8,253		7,501		7,276		4,201		4,821
Total fixed charges	$	168,714	$	213,973	$	202,465	$	208,226	$	206,089	$	219,437
Preferred Stock Dividend Requirements:
Income before income taxes attributable to common shareholders	$	704,324	$	678,445	$	674,977	$	618,300	$	636,665	$	624,697
Net income from continuing operations attributable to common shareholders	466,827		442,034		437,257		397,595		406,074		387,380
Ratio of income before income taxes to net income	1.51		1.53		1.54		1.56		1.57		1.61
Preferred stock dividends	—		—		—		—		—		—
Preferred stock dividend requirements — ratio (above) times preferred stock dividends	$	—	$	—	$	—	$	—	$	—	$	—
Fixed Charges and Preferred Stock Dividend Requirements:
Fixed charges	$	168,714	$	213,973	$	202,465	$	208,226	$	206,089	$	219,437
Preferred stock dividend requirements	—		—		—		—		—		—
Total	$	168,714	$	213,973	$	202,465	$	208,226	$	206,089	$	219,437
Ratio of Earnings to Fixed Charges (rounded down)	5.17		4.17		4.33		3.96		4.08		3.84