Schedule II - Valuation Reserves

12 Months Ended

Sep. 30, 2025

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

Schedule II - Valuation Reserves

Schedule II — Valuation Reserves

Compass Minerals International, Inc.

September 30, 2025, 2024 and 2023

Description (in millions)	Balance at the Beginning of the Period		Additions Charged to Expense		Deductions(1)		Balance at the End of the Period
Deducted from Receivables — Allowance for Credit Losses
September 30, 2025	$	3.6	$	3.5	$	(4.9)	$	2.2
September 30, 2024	2.3		3.5		(2.2)		3.6
September 30, 2023	3.4		2.2		(3.3)		2.3
Deducted from Deferred Income Taxes — Valuation Allowance
September 30, 2025	$	167.3	$	33.1	$	(1.5)	$	198.9
September 30, 2024	121.2		46.2		(0.1)		167.3
September 30, 2023	109.9		12.1		(0.8)		121.2

(1)Deduction for purposes for which reserve was created.