16 Intangible assets

	Goodwill £’000	Registrations £’000		Other intangible assets £’000		Total £’000
At 1 July 2018
Cost	421,453	785,594		10,379		1,217,426
Accumulated amortization	—	(416,086	)	(1,700	)	(417,786	)

Net book amount	421,453	369,508		8,679		799,640

Six months ended 31 December 2018
Opening net book amount	421,453	369,508		8,679		799,640
Additions	—	14,461		1,871		16,332
Disposals	—	(7,929	)	—		(7,929	)
Amortization charge	—	(66,947	)	(1,624	)	(68,571	)

Closing book amount	421,453	309,093		8,926		739,472

At 31 December 2018
Cost	421,453	764,746		12,250		1,198,449
Accumulated amortization	—	(455,653	)	(3,324	)	(458,977	)

Net book amount	421,453	309,093		8,926		739,472


At 1 July 2017
Cost	421,453	645,433		6,619		1,073,505
Accumulated amortization	—	(354,913	)	(1,048	)	(355,961	)

Net book amount	421,453	290,520		5,571		717,544

Six months ended 31 December 2017
Opening net book amount	421,453	290,520		5,571		717,544
Additions	—	126,912		1,853		128,765
Disposals	—	(2,844	)	—		(2,844	)
Amortization charge	—	(72,756	)	(633	)	(73,389	)

Closing book amount	421,453	341,832		6,791		770,076

At 31 December 2017
Cost	421,453	730,926		8,472		1,160,851
Accumulated amortization	—	(389,094	)	(1,681	)	(390,775	)

Net book amount	421,453	341,832		6,791		770,076

Impairment tests for goodwill

Goodwill is not subject to amortization and is tested annually for impairment (normally at the end of the third fiscal quarter) or more frequently if events or changes in circumstances indicate a potential impairment. Management has considered the carrying amount of goodwill as of 31 December 2018 and concluded that, as there are no indicators of impairment, a detailed impairment test is not required. Having assessed the future anticipated cash flows, management believes that any reasonably possible changes in key assumptions would not result in an impairment of goodwill.

Other intangible assets

Other intangible assets include internally generated assets whose cost and accumulated amortization as of 31 December 2018 was £1,559,000 and £275,000 respectively (31 December 2017: £1,219,000 and £nil respectively).