Revenues (Tables)

3 Months Ended

Mar. 31, 2026

Revenue from Contract with Customer [Abstract]

Disaggregation of 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 March 31
(Millions of Dollars)	2026		2025
Major revenue types
Revenue from contracts with customers:
Residential	$	98	$	114
C&I	298		288
Other	11		11
Total retail	407		413
Wholesale	30		25
Transmission	84		76
Other	1		1
Total revenue from contracts with customers	522		515
Alternative revenue and other	8		6
Total revenues	$	530	$	521