Revenues

9 Months Ended

Sep. 30, 2025

Revenue from Contract with Customer [Abstract]

Revenue

Revenue is classified by the type of goods/services rendered and market/customer type. SPS’ operating revenues consisted of the following:

	Three Months Ended Sept. 30
(Millions of Dollars)	2025		2024
Major revenue types
Revenue from contracts with customers:
Residential	$	153	$	152
C&I	359		308
Other	16		14
Total retail	528		474
Wholesale	33		29
Transmission	84		80
Other	—		1
Total revenue from contracts with customers	645		584
Alternative revenue and other	10		10
Total revenues	$	655	$	594

	Nine Months Ended Sept. 30
(Millions of Dollars)	2025		2024
Major revenue types
Revenue from contracts with customers:
Residential	$	362	$	321
C&I (a)	936		744
Other	39		36
Total retail	1,337		1,101
Wholesale	81		95
Transmission	238		221
Other	2		2
Total revenue from contracts with customers	1,658		1,419
Alternative revenue and other	26		61
Total revenues	$	1,684	$	1,480

(a)For the nine months ended Sept. 30, 2025 and 2024, revenues from one C&I customer represented approximately 9.3% and 10.1% of total revenues, respectively.