How do you treat recoverable of bad debts in the of accounts which you have already write off in previous year?

If the bad debt is recovered, that amount should be treated as other income and shown in the P&L account.

Entry is :   Cash A/c Dr.

                 To Bad Debt Recoved(other Income) 

Suspance ac debit 

      Profit & Loss Ac Credit

journal voter has to pass from party account debiting and the bad debts account credited