Schedule II, Valuation and Qualifying Accounts

12 Months Ended

Dec. 31, 2020

SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]

Schedule II, Valuation and Qualifying Accounts

Public Service Co. of Colorado and Subsidiaries Valuation and Qualifying Accounts Years Ended Dec. 31

	Allowance for bad debts
(Millions of Dollars)	2020		2019		2018
Balance at Jan. 1	$	21	$	21	$	20
Additions charged to costs and expenses	24		17		16
Additions charged to other accounts (a)	4		6		5
Deductions from reserves (b)	(20)		(23)		(20)
Balance at Dec. 31	$	29	$	21	$	21

(a)Recovery of amounts previously written-off.

(b)Deductions related primarily to bad debt write-offs.