Bad debt deduction rules allow write-off claims only for actual irrecoverable debts included in income or lending business advances. Deduction is allowable for actual bad debts written off as irrecoverable in the assessee's accounts, provided the debt was taken into account in computing income of the relevant year or an earlier year, or represents money lent in the ordinary course of banking or money-lending business. The deduction applies only on write-off, excludes provision for bad and doubtful debts, and covers later recovery only to the extent of any shortfall. Amounts included in income under notified computation rules may also be treated as written off for this purpose.