Intangible Assets

3 Months Ended

Dec. 31, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

The gross and net carrying values of intangible assets as of the balance sheet dates, by major intangible asset class are as follows (in millions):


	December 31, 2023						September 30, 2023
	Gross Amount		Accumulated Amortization		Net Amount		Gross Amount		Accumulated Amortization		Net Amount
Intangible assets subject to amortization
Trade/domain names	$	4.1	$	(2.6)	$	1.5	$	4.1	$	(2.4)	$	1.7
Software programs/platforms	4.9		(3.5)		1.4		28.5		(26.9)		1.6
Client and supplier base	34.1		(21.5)		12.6		38.3		(24.1)		14.2
Total intangible assets subject to amortization	43.1		(27.6)		15.5		70.9		(53.4)		17.5

Intangible assets not subject to amortization
Website domains	2.0		—		2.0		1.9		—		1.9
Business licenses	3.7		—		3.7		3.7		—		3.7
Total intangible assets not subject to amortization	5.7		—		5.7		5.6		—		5.6
Total intangible assets	$	48.8	$	(27.6)	$	21.2	$	76.5	$	(53.4)	$	23.1

Amortization expense related to intangible assets was $2.0 million and $3.9 million for the three months ended December 31, 2023 and 2022, respectively.

The Company wrote off $27.8 million of fully amortized intangible assets during the three months ended December 31, 2023.

As of December 31, 2023, the estimated future amortization expense was as follows:


(in millions)
Fiscal 2024 (remaining nine months)	$	4.7
Fiscal 2025	3.6
Fiscal 2026	2.8
Fiscal 2027	2.2
Fiscal 2028 and thereafter	2.2
Total intangible assets subject to amortization	$	15.5