22. Trade and other receivables


All figures in £ millions	2017		2016
Current
Trade receivables		739		961
Royalty advances		8		22
Prepayments		82		124
Accrued income		1		15
Other receivables		280		235

		1,110		1,357

Non-current
Trade receivables		21		21
Royalty advances		20		10
Prepayments		15		13
Accrued income		10		31
Other receivables		37		29

		103		104

The carrying value of the Group’s trade and other receivables approximates its fair value. Trade receivables are stated net of provisions for bad and doubtful debts and anticipated future sales returns. The movements in the provision for bad and doubtful debts are as follows:


All figures in £ millions	2017			2016
At beginning of year		(112	)		(64	)
Exchange differences		7			(17	)
Income statement movements		(38	)		(53	)
Utilised		21			22
Disposal through business disposal		1			—
Transfer to assets classified as held for sale		5			—

At end of year		(116	)		(112	)

Concentrations of credit risk with respect to trade receivables are limited due to the Group’s large number of customers, who are internationally dispersed.

The ageing of the Group’s trade receivables is as follows:


All figures in £ millions	2017			2016
Within due date		661			812
Up to three months past due date		187			232
Three to six months past due date		48			55
Six to nine months past due date		18			21
Nine to 12 months past due date		13			14
More than 12 months past due date		3			7

Total trade receivables		930			1,141
Less: provision for sales returns		(170	)		(159	)

Net trade receivables		760			982

The Group reviews its bad debt provision at least twice a year following a detailed review of receivable balances and historical payment profiles. Management believes all the remaining receivable balances are fully recoverable.