No it is not. There is no rule as such. No IFRS specifies a period afer which a debtor should be treated as doubtful. In fact as per IAS 39 you can not make a provision for a specific debtor simply because that debtor remains outstanding for a particular period. In other words IFRS does not permit provision for doubtful debts based on debtors aging. For instance you can NOT have a system where you provide 50% for debtors outstanding between 06 to 12 months & 100 % provision for debtors outstanding over one year.
As per IAS 39 trade debtors are financial assets and therefore you have to test debtors for any impairment losses.
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