The term bad debts usually refers to accounts receivable (or trade accounts receivable) that will not be collected.  However, bad debts can also refer to notes receivable that will not be collected.

The bad debts associated with accounts receivable is reported on the income statement as Bad Debts Expense or Uncollectible Accounts Expense.

When the allowance method is used, the journal entry to Bad Debts Expense will include a credit to Allowance for Doubtful Accounts, a contra account and valuation account to the asset Accounts Receivable. The allowance method anticipates the losses and therefore requires the use of estimates.

Under the direct write-off method, the Allowance for Doubtful Accounts is not used. Rather, Bad Debts Expense will be debited when an account receivable is actually written off. The credit in this entry will be to the asset Accounts Receivable.