2002 £m	2001 £m
Trade debtorsa	2,393	3,379
Amounts owed by joint ventures (trading)	582	532
Amounts owed by associates (trading)	1	5
Other debtors	664	506
Accrued income	1,262	1,420
Pension fund prepayment (note 27)	231	-
Other prepayments	139	418
Total debtors	5,272	6,260

^aTrade debtors are stated after deducting £450 million (2001 - £487 million) for doubtful debts. The amount charged to the group profit and loss account for doubtful debts for the year ended 31 March 2002 was £369 million (2001 - £227 million, 2000 - £264 million), including an exceptional charge of £79 million.